The present invention relates to a medicament delivery device comprising a housing, arranged to accommodate a medicament container; a power unit arranged inside said housing, said power unit comprising a plunger rod, a drive spring operably arranged to act on the plunger rod and, which is, upon activation, operably arranged to act on said medicament container, an actuator comprising holding elements, capable of releasably holding said plunger rod with said drive spring in a tensioned state, and an actuator sleeve operably connected to said actuator for releasably locking said holding elements in a holding state; said medicament delivery device further comprising a medicament delivery member guard slidably movable in said housing and arranged to act on said actuator sleeve for setting said holding elements with said actuator sleeve in a first activation state; an activator unit arranged to be manually operated and, which is, operably connected to said plunger rod for setting said holding elements with said actuator sleeve in a second activation state, wherein said plunger rod is released when both activation states are set.