The invention relates to a medicament delivery device comprising a housing arranged to receive a medicament container (20), a drive unit (25) arranged to act on a stopper (27) in said medicament container (20), which drive unit (25) comprises a torsion drive spring (50). A dose setting member (56) is operably connected to said drive unit (25) such that a manual turning of said dose setting member (56) causes a tensioning of said torsion drive spring (50). The device further comprises an activation mechanism (76) having an activation button (94) protruding through the distal end of the device, wherein said activation mechanism (76) is operably connected to said drive unit (25) such that actuation of said activation mechanism (76) causes a release of said drive unit (25) whereby a set dose of medicament is delivered.
