Ilmenau was historically a small mining town, primarily silver, copper and manganese, until the deposits were depleted.

Industrialisation started after the railway arrived in 1879, but increased rapidly during the following century primarily in glass and porcelain manufacturing.

The glass industry, however, remained and produces laboratory equipment and measurement devices and is leading source of economic activity together with mechanical, electrical, and software engineering.

Ilmenau and the surrounding region have produced many winter Olympic champions in disciplines such as luge, bobsleigh, and biathlon.

It is possible that the village was founded by the St. Peter's monastery of Saalfeld, which encouraged the settlement of this part of Thuringia during the High Middle Ages.

After 1320, an important trade route from Nuremberg in the south to Erfurt in the north was relocated next to Ilmenau, so that a castle was established to control the traffic.

A brief revival of copper mining under the leadership of Johann Wolfgang von Goethe failed during the first decades of the 19th century.

After the Hennebergs died out in 1583, the city belonged to the Wettins and since 1661 to the Wettin-Ernestine duchy of Saxe-Weimar (until the end of monarchy in Germany in 1918).

Some factories for porcelain (Graf von Henneberg Porzellan since 1777), glasswares (the Sophienhütte since 1852) and toys developed and grew until the Great Depression.

It weakened especially private consumption, so that Ilmenau's toy industry collapsed, same as some porcelain producers focused on bibelot.

In December 2011, the Horten V3 was transferred to the Smithsonian Institution's Paul E. Garber Restoration Facility in Suitland, Maryland, US.

Ilmenau is located within a basin, formed by Ilm river on the northern edge of the Thuringian Forest at an altitude of 500m.

The surrounding mountains are the Pörlitzer Höhe (573 m) in the north, the Ehrenberg (528 m) and the Tragberg (534 m) in the east, the Lindenberg (749 m) in the south, the Kickelhahn (861 m) in the south-west and the Hangeberg (701 m) in the west.

This lies between the old town and the main campus of the university with 5 lakes, laid out by monks during the Middle Ages for providing fish.

The forest monocultures of spruces were caused by the enormous need of wood for mining and glass industry during the previous centuries.

Ilmenau abuts the following municipalities, which are all part of the Ilm district: Neusiß, Plaue and Wipfratal in the north, Wolfsberg and Langewiesen in the east, Stützerbach, Schmiedefeld am Rennsteig and Gehlberg in the south as well as Elgersburg and Martinroda in the west.

The unfavourable economic situation in the old East Germany after reunification in 1990 resulted in a decline in the population, which fell to 27,000 in 2000 before stabilising.

It occurred after reunification for a short time in the 1990s, but most of the suburban areas were situated within the administrative city borders (e.g. Oberpörlitz and Hüttenholz settlement), others were Langewiesen or Elgersburg.

Like other eastern German cities, Ilmenau has only a small immigrant population: circa 4.4% are non-Germans by citizenship and overall 9.5% are migrants (according to 2011 EU census).

During recent years, the economic situation of the city has improved: the unemployment rate within the Ilm district has declined from 21% in 2005 to 7% in 2013.

The town centre is located between Obertorstraße in the north, Poststrasse in the east, Mühlgraben in the south and Burggasse in the west.

Between 1871 and 1914, some interesting parts of the town with large villas developed: a larger one in the south-west around Waldstraße and Goetheallee and a smaller one in the west around Sturmheide, which are hosting noble mansions in Gründerzeit and Art Nouveau style.

During the GDR period, two big Plattenbau estates were established in the south-east ("Stollen") and in the north ("Pörlitzer Höhe").

The porcelain industry did not survive the structural change after German reunification in 1990, so that factories closed like most in Western Germany earlier during the 1970s and 1980s.

The glass industry always concentrated on laboratory glassware such as thermometers, test tubes and other chemical and medical requisites.

After reunification, the factory survived and is still a leading company for laboratory glassware in Germany, nevertheless, due to rationalization efforts during the 1990s, the number of employees decreased to 225.

There is the Ilm track from the Rennsteig in the Thuringian Forest to the Saale valley at the Saxony-Anhalt border via Ilmenau and Weimar.

In addition there are cycle paths that connect to the Gera track (in Elgersburg) to Erfurt nearby and to the Saale valley in the east via Gehren, Königsee and Rudolstadt.

Public transport includes a bus network connecting the city centre with the outskirts and neighbouring villages.