The present invention relates to a medicament delivery device comprising a generally elongated housing (10) having a distal end (12) and a proximal end (14) along a longitudinal axis (L), the housing (10) being arranged to accommodate a medicament container (18) enclosing a medicament, and a medicament delivery member (20) connected to the medicament container(18)； a reloadable drive mechanism (26) capable of, upon activation, act on said medicament container (18)； a medicament delivery member cover (54) operably arranged at the proximal end of the device and slidable in relation to the housing (10) along the longitudinal axis (L)； wherein the device further comprises a medicament delivery member cover lock mechanism (90) comprising: a first lock member (106) provided on an actuator (92) that is movably arranged in relation to the housing； and a second lock member (104) provided on said medicament delivery member cover (54), wherein the first lock member is operably engageable with the second lock member for blocking movement of said medicament delivery member cover (54) and wherein the actuator (92) is movable in relation to the medicament delivery member cover (54), such that manual actuation of said actuator (92) in a direction generally transversal to the longitudinal axis (L) causes the first lock member (106) to be moved out of engagement with the second lock member (104) of said medicament delivery member cover (54), thereby allowing said medicament delivery member cover (54) to be moved.
