The present invention relates to a medicament delivery device comprising a housing (12) a medicament container (14) arranged within said housing medicament delivery drive means (22, 24) manually operable release means (38) and a movement speed control mechanism (44, 46, 48) comprising at least one fixed, flexible and elongated compartment (48) containing a liquid, and at least one flexible speed control member (44, 46) connected to the medicament delivery drive means wherein said at least speed control member is arranged to be pressing on said at least one compartment for forcing said liquid past said member and thereby creating a movement speed control of said medicament delivery drive means when moved.
