The disclosure relates to medicament delivery device including an activating mechanism, wherein the activating mechanism includes a hollow injection needle, a cartridge containing a dosage of a medicament, a cartridge carrier including at least one resilient arm for holding the cartridge, a removable needle cap for covering the injection needle, and a drive element adapted to couple with the cartridge, wherein the cartridge is retained in a position spaced apart from the injection needle in a proximal direction (P) by the at least one resilient arm when the medicament delivery device is in an initial position (P1), and wherein by removing the needle cap, the cartridge is releasable to be pushed into a distal direction (D) by the drive element with respect to the cartridge carrier.