A native Parisian, at the age of twenty, he became an assistant-naturalist with the French National Museum of Natural History.

His observation, in 1809, that each plant cell is contained in a continuous membrane, remains a central contribution to cytology.

His 1802 treatise and these publications enabled him, in 1808, to join the French Academy of Sciences and to become the chair of the botany department of the Sorbonne.

With the Bourbon Restoration, Mirbel's friend Élie, duc Decazes, then Minister of Interior, offered him the post of Secretary General.

But the fall of the government in 1829, marked the end of Mirbel's political career, and he returned to a position with the National Museum of Natural History as head of the Jardin des Plantes in Paris, and eventually became the Director of Culture (chaire de culture) for the museum.