A medicament delivery device includes a housing having a proximal housing part and a distal housing part movable relative each other, a drive force mechanism accommodated in the distal housing part, a container filled with medicament arranged within the proximal housing part, a holding member for holding the drive force mechanism in a loaded state, and an actuation member arranged to interact with the holding member for releasing the drive force mechanism from its loaded state. The holding member is arranged to be moved from a disengaged position, in which the holding member is disengaged from the actuation member, to an engaged position, in which the holding member is engaged to the actuation member by moving the housing parts in relation to each other.
