Medicament delivery device comprising: - a housing (16, 18), 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 (94, 100), capable of releasibly holding said plunger rod with said drive spring in a tensioned state, and an actuator sleeve operably connected to said actuator for releasibly locking said holding elements (94, 100) in a holding state, wherein said holding elements (94, 100) comprise a number of tongues arranged with ledges arranged to engage recesses in said plunger rod; said medicament delivery device further comprising: - a medicament delivery member guard slidably movable in a distal direction in said housing (16, 18) and arranged to act on said actuator sleeve for moving said actuator sleeve distally in relation to the actuator and for setting said holding elements (94, 100) with said actuator sleeve in a first activation state; and - an activator unit comprising push elements arranged to act on an end surface of said plunger rod, wherein said activation unit is slidably movable and arranged to be manually operated in a proximal direction to move said plunger rod and thereby said holding elements (94, 100) proximally for setting said holding elements (94, 100) with said actuator sleeve in a second activation state, wherein said plunger rod is released when both activation states are set; and wherein the drive spring is operably arranged between the plunger rod and the actuator, the medicament delivery device further comprising a medicament delivery member guard spring arranged to force said medicament delivery member guard in a proximal direction after removal of said medicament delivery device, the medicament delivery device further comprising a medicament delivery member guard locking mechanism, wherein said medicament delivery member guard locking mechanism comprises said tongues of said holding elements (94, 100) interacting with a distally directed ledge on an inner surface of said actuator sleeve such that movement of said medicament delivery member guard in the proximal direction will cause said tongues to pass said ledge and flex in a generally radial direction, whereby the engagement of the tongues with the ledge will lock any movement of medicament delivery member guard in the distal direction, and the medicament delivery device further comprising a medicament delivery member guard locking signal mechanism, wherein said medicament delivery member guard locking mechanism comprises said tongues of said holding elements (94, 100) interacting with a distally directed ledge on an inner surface of said actuator sleeve such that movement of said medicament delivery member guard in the proximal direction will cause said tongues to pass said ledge and flex in a generally radial direction, generating a medicament delivery member guard locking signal. - a housing (16, 18), 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 (94, 100), capable of releasibly holding said plunger rod with said drive spring in a tensioned state, and an actuator sleeve operably connected to said actuator for releasibly locking said holding elements (94, 100) in a holding state, wherein said holding elements (94, 100) comprise a number of tongues arranged with ledges arranged to engage recesses in said plunger rod; said medicament delivery device further comprising: - a medicament delivery member guard slidably movable in a distal direction in said housing (16, 18) and arranged to act on said actuator sleeve for moving said actuator sleeve distally in relation to the actuator and for setting said holding elements (94, 100) with said actuator sleeve in a first activation state; and - an activator unit comprising push elements arranged to act on an end surface of said plunger rod, wherein said activation unit is slidably movable and arranged to be manually operated in a proximal direction to move said plunger rod and thereby said holding elements (94, 100) proximally for setting said holding elements (94, 100) with said actuator sleeve in a second activation state,