A medicament delivery device having a housing, arranged to accommodate a medicament container and a power unit, where the power unit has a plunger rod, a drive spring, operably arranged to act on the plunger rod and on said medicament container, an actuator having holding elements that can releasably hold the 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. The medicament delivery device also can have a medicament delivery member guard slidably movable in said housing that can 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.
