A medicament delivery device comprising a housing, a tubular activation member, a first resilient member, a container holder, a medicament container (80), a tubular operation member (100), a plunger rod (90), a delivery member wherein the container is a cartridge, having a membrane (82) and in that the delivery member comprises a retainer member (70) fixedly connected to the container holder, a hub (60) coaxially movable within the retainer member, a needle having opposite proximal and distal ends, and a cap (10) interactively connected to the hub and to the retainer member, wherein the cap comprises a distal end surface abutting with the proximal end surface of the annular contact member such that said hub may be distally moved whereby the needle penetrates the membrane and the cap is detached from the retainer member, allowing the tubular activation member to be moved its activated position.
