Dedicated to Natural History, the Muséum d'Angers houses in its collections about 530,000 objects, including 3,000 birds, 20,000 shells, 50,000 fossils, 80,000 insects and 350,000 herbarium samples, as well as hundreds of specimens taxidermised or in liquid, skeletons, minerals, technical instruments and Documents.

By the Decree of 22 November 1790, Gabriel Eleanor Merlet de la Boulaye (1736–1807) is assigned the gathering of all books and natural history collections seized in the national houses.

La Révellière-Lépeaux invited Renou to Paris in 1798, where he was allowed to receive objects from the National Museum of Natural History, including a group of 12 fossil fish brought from Italy (Monte Bolca) by Bonaparte in 1797, which still exists with their original labels.

The main site of the museum remained the Barrault House, but in 1885, the town of Angers decided to purchase the Soye collection, which consisted of several thousand fossil samples.

In the same year, a Holzmaden ichthyosaur cast is added to the collections, purchased at the Cantonal Museum of Geology in Lausanne, where the original still stands.

Preserved in the Jardin des Plantes during most of the 19th century, the herbaria were re-housed in 1895 in the Old Mansion House, the north wing of the Old Town Hall, adjacent to the Palaeontological Museum.

Under the director Georges Bouvet (1850–1929) many objects entered the museum (the number of samples has more than quintupled) and a general classification of the specimens was completed.

The two establishments were eventually reunited to recreate the Museum of Natural History in 1990, and the two buildings were connected in 1991 through a path along the ancient walls of the town of Angers, allowing visitors a continuous journey between the zoological rooms and the palaeontology gallery.

The Muséum d'Angers follows the National Museum by adopting five main missions:[7] curation of collections, dissemination of knowledge, expertise, pedagogy, and scientific research (yet the latter two are only achieved in Angers through mediation, object loans and hosting of trainees and external researchers; a scientific project is sometimes set up under the purview of the Muséum).

It is part of networks dedicated to museums and contributes to national and international patrimonial databases for the benefit of scientists and the general public.

The Muséum d'Angers subscribes to ICOM's definition of museum and is thus "a non-profit, permanent institution in the service of society and its development, open to the public, which acquires, conserves, researches, communicates and exhibits the tangible and intangible heritage of humanity and its environment for the purposes of education, study and enjoyment".

The interior layout of the Demarie-Valentin House is surprisingly unique in its neoclassical style: through the front door, a high staircase leads on to a round courtyard dominated by a circular balcony.

As the Muséum d'Angers is part of an environmental education programme, themes and pedagogical cards adapted to all school grades are available for teachers.

Finally, the Muséum d'Angers participates every year in international cultural events such as the European Heritage Days and the Long Night of Museums.

The botanical collections represent numerically the greatest heritage in the Muséum d'Angers, with more than half of the total number of museum objects.

[13] They are organised around three important collections:[14][15] the general herbarium, that of Alexandre Boreau, and that of James Lloyd, the three herbaria together making up about 80% of the total samples.

The general herbarium contains several type-specimens, including types from the island of Réunion, the collections of Philibert Commerson (voyage of Bougainville), Jacques Labillardière (expedition of Entrecasteaux), Pierre Antoine Poiteau (Santo Domingo) and even some rare samples from the seventeenth century.

The Boreau herbarium contains probably more than 100,000 samples, including material used for the writing of the Flore du centre de la France, the most famous regional flora of its time.

There are also herbaria of mosses (Bouvet, Bruneau), lichens (Decuillé, Thuillier), fungi (Gaillard, Guépin, Rabenhorst) and algae (Lloyd, Bory, Corillion).

There are also specimens belonging to extinct species, including a Carolina parakeet and a passenger pigeon; casts of an Aepyornis egg and of a moa's leg bones can be seen.

The Muséum d'Angers has important collections of paleontology (50,000 fossils, including palaeobotany, paleozoology and paleoichnology) tracing the history of life since the Cambrian, 500 million years ago.

The Maine-et-Loire fossils come mainly from local Cretaceous tuffeau limestone and Tertiary faluns, but also from fossiliferous Armorican levels such as Ordovician or Devonian.

A composite skeleton of the Miocene fossil sirenian Metaxytherium medium, an ancestor of the extant dugong, is a major asset of the palaeontological collections.

The systematic excavations of Michel Gruet (1912–1998) in the 1940s–1980s were particularly fortunate, and the discovery of Neanderthal bones (maxilla, isolated tooth and humerus), partially exhibited at the Muséum d'Angers, confirmed the importance of the site for the study of prehistory in Anjou and in Europe.

2019 « Insula Utopia / Inventaire du Ciel », works and installations by Richard Rak[20] 2018 « Hungry Planet », photography by Peter Menzel and Faith d'Aluisio[21] 2018 « La grande parade des animaux », at the Musée des Beaux-Arts d'Angers[22] 2018 « HerbEnLoire : trésors retrouvés »[23] 2017 « Les animaux du noir », photography by Katrin Backes and Sylvain Tanquerel[24] 2017 « Drôles d'oiseaux »[25] 2016 « L'aventure botanique des Caraïbes aux bords de la Loire »[26] 2015 « Bestioles d'Anjou », photography by Sylvie Mercier[27] 2015 « Gravex naturalis : espèce en voie d'exposition »[28] 2015 « Sols fertiles, vie secrètes »[29] 2014 « Zoos humains : l'invention du sauvage »[30] 2014 « Traces des absents », works by Hélène Gay[31] 2014 « Récolement ?

10 ans de récolement des collections »[32] 2014 « Portraits de famille », works by Hélène Benzacar[33] 2014 « Flore », paintings by Catherine Brasebin[34] 2013 « Espèces en folie »[35] 2013 « Alarme et camouflage »[36] 2012 « Écorces », photography by Cédric Pollet[37] 2012 « Art d'ici : univers singuliers », painting/sculpture (Société des Artistes Angevins)[38] 2011 « Safari urbain », photography by Laurent Geslin[39] 2011 « Abriter les papillons », at the Arboretum Gaston-Allard[40] 2010 « Biodiversité : le Muséum sort de sa réserve »[41] 2009 « Darwin : mission Galápagos », bicentennial[42] 2009 « J'ai capturé dans mes filets », writing by Thérèse Bonnétat and tapestries by Muriel Crochet[43] 2008 « L'Anjou sous nos pieds », geology of Anjou[44] 2008 « Curieuses invitées », works by Juliette Vicart[45] 2008 « L'animal griffé », drawings and sculptures by Delphine Izzo[46] 2007 « Double visite : 5 artistes au Muséum » 2007 « Nom : Carl v. Linné, Profession : naturaliste », tricentennial[47] 2006 « Amazone nature » 2006 « Ligne du Monde » 2006 « Naturellement Loire... une escale en Anjou » 2005 « Réserves », photography by Hélène Benzacar »[48] 2005 « Voyage dans la troisième dimension », hologrammes[49] 2005 « Photographes de nature », photography by BBC Wildlife Magazine 2005 « Chauves-souris de chez nous » 2004 « Forêt ou le frémissement des limbes », photography by Laurent Vergne[50] 2004 « Histoires naturelles », works by Sylvie Mercier de Flandre 2004 « La faune du Mali » 2003 « Algérie, deux millions d'années d'histoire : les premiers habitants » 2003 « Madagascar : l'île aux trésors » 2002 « Félins du monde » 2002 « Lumières Polaires et aurores boréales », photography by Rémy Marion 2001 « Rue des Sciences : les noms de rues dédiés aux scientifiques » 2001 « La Nature, quelle artiste » 2001 « Paysage du monde, paysage d'Anjou » 2000 « Le pétrole dans tous ces états », Fête de la Science 2000 « La ménagerie du roi René » 1999 « Trésors botaniques d'Angers » 1999 « Le petit peuple des champs et des bois », photography by Michel Beucher 1998 « Rêveur au long cours », installations by Richard Rak[51] 1996 « Ages et images de la terre » 1994 « Baleines en vue » 1993 « Point Info dinosaures » 1990 « Roc en Pail – 50 000 ans de préhistoire angevine », an exhibition presenting results from Michel Gruet's archaeological excavations at Roc-en-Pail; parts of this exhibition can still be visited in the permanent exhibition of the Muséum d'Angers[52] a at the same time Director of the Jardin des plantes d'Angers b at the same time Director of the Musée Paléontologique (créé 1885) c Georges Bouvet was at the same time Director of the Muséum and of the Musée Paléontologique (1895–1929), Director of the Jardin des plantes (1895–1929) and Director of the Musée Botanique (1904–1929) d Philippe Maury was at the same time Director of both Musées Paléontologique and Zoologique (established 1958) and Director of the Musée Botanique e Director of both Musées Paléontologique and Zoologique, reunited in 1990