The present disclosure relates to a medicament delivery device (1) for injection of a medicament. The medicament delivery device (1) comprises a housing (5) arranged to receive a medicament container assembly, an activation member (7) axially movable relative to the housing (5) between an extended position and a retracted position to expel medicament from the medicament container assembly, which activation member (7) comprises a gripping member, and wherein the housing (5) and the activation member (7) comprises a movement guide mechanism comprising a first guide, a second guide which has a locking portion, and a guide follower, wherein the guide follower is arranged to slide along the first guide when the activation member (7) is moved from the extended position to the retracted position for expelling medicament, wherein the gripping member is arranged to engage the medicament container assembly when the activation member (7) is in the retracted state, and wherein the guide follower is arranged to slide along the second guide when the activation member (7) is moved back from the retracted position to the extended position, and wherein the locking portion is arranged to interact with the guide follower when the activation member (7) has been moved back from the retracted position to the extended position to restrict movement of the activation member (7) relative to the housing (5). The present disclosure also relates to a method of assembling a medicament delivery device.La présente invention concerne un dispositif dadministration de médicament (1) destiné à linjection dun médicament. Le dispositif dadministration de médicament (1) comprend un logement (5) agencé pour recevoir un ensemble de récipient de médicament, un élément dactivation (7) axialement mobile par rapport au logement (5) entre une position déployée et une position rétractée pour expulser un médicament de lensemble de récipient de médicament, lélément dactivation (7) comprenant un élément de préhensi
