The present invention relates to a medicament delivery device (10) comprising a housing (12, 14)； a medicament container holder (90), arranged movable in relation to said housing (12, 14) and capable of accommodating a medicament container (92)； an biased activator (160) comprising a plunger rod (164), which plunger rod (164) is arranged to act on the medicament container (92) for delivering a dose of medicament through a medicament delivery member (102 when said biased activator (160) is operated； a manually operable dose setting member (72) operably connected to both said housing and said medicament container holder such that manual operation of said dose setting member (72) will cause the medicament container holder (90) with the medicament container (92) to move towards said plunger rod (164) for setting a dose of medicament to be delivered； a dose drum (56) releasably connected to the dose setting member (72) through a releasable connection mechanism (68, 84I) such that when the dose setting member is operated, said dose drum (56) is displaced from an initial position to a set dose position； a release mechanism (116) operably connected to said biased activator (160), wherein, when said plunger rod (164) is moved to an end position of the dose delivery operation, said release mechanism (116) is arranged to act on said connection mechanism (68, 84I) for releasing said dose drum (56) from said dose setting member (72). The invention is characterised in that said release mechanism is arranged with a locking mechanism (130, 84II) arranged to lock said dose setting member (72) from displacement as the connection mechanism (68, 84I) is operated for releasing said dose drum (56) from said dose setting member (72).La présente invention concerne un dispositif d'administration de médicament (10) comprenant un boîtier (12, 14) ； un support de récipient de médicament (90), placé de manière mobile par rapport audit boîtier (12, 14) et apte à recevoir un récipient de médicame
