The present disclosure relates to a medicament delivery device comprises: a housing having a proximal end and a distal end； a medicament container positioned in the housing and having a medicament delivery member shield； a medicament delivery mechanism associated with the medicament container； an activation member operably connected to the medicament delivery mechanism and longitudinally movable in relation to the housing from an extended position to a retracted position to activate the medicament delivery mechanism； and a removable cap assembly comprising a deshielder, an inner tubular integrity lock member having a resilient structure configured to interact with both a first engaging structure of the activation member and a second engaging structure of the housing for preventing the activation member from moving into the retracted position； and wherein the removable cap assembly further comprises an outer tubular cap body which is movable in relation to the housing and to the inner tubular integrity lock member from an initial position in which the outer tubular cap body is releasibly connected to the housing and is disengaged from the inner tubular integrity lock member, to an intermediate position in which the outer tubular cap body is partially disengaged from the housing for giving tamper proof indication and in which the outer tubular cap body is fixedly engaged to the inner tubular integrity lock member for allowing the removal of the medicament delivery member shield.
