Medicament delivery device comprising: which extends along a longitudinal axis and comprises:a generally tubular elongated housing having a proximal and a distal end, which generally tubular elongated housing is arranged to accommodate a medicament container (28)； a drive unit comprising a drive element (116) and plunger rod (68) operably arranged to act on said medicament container (28)；a tubular element (72) rotatable arranged in relation to said housing and operably arranged to said plunger rod(68).The invention is characterised in that the plunger rod comprises at least one holding member (80) and in that the tubular element (72) comprises at least one arm (78) extending generally transversal to the longitudinal axis of the device, wherein the at least one arm (78) is arranged to engage the at least one holding member (80) on said plunger rod (68) to releasable hold said drive unit in an energy accumulated state.
