Abstract: An active substance depot for an inhalation device having a depot body externally sealed in an airtight manner prior to use, comprising at least one segment made from a plastic material, having a flow channel to be unsealed for use, and having at least one active substance carrier provided in the flow channel in which is stored at least one volatile substance at least partially transitioning into the gaseous phase when heated, the active substance carrier being heated for releasing the substance. According to the invention, the plastic material of which the segment of the depot body is made is a polymer from the group of cyclo olefin copolymers, and the segment of the depot body made from the polymer comprises an opening connected to the flow channel, said opening being sealed by a foil made of a second material, and said foil being removed or punctured immediately prior to use.