The invention relates to a medicament delivery device (100) having having a a drive mechanism arranged to drive a plunger rod (12). A release button (4) is movable between an active and an inactive state, wherein the release button (4) in the active state allows the actuator (3) to move axially towards a proximal end position and wherein the release button (4) in the inactive state allows the actuator (3) can move axially towards the proximal end position or towards the distal end position.本發明有關具有一被配置來驅動柱塞桿(12)之驅動機構的藥物遞送裝置(100)。釋放按鈕(4)係可於活動及不活動狀態之間運動,其中於該活動狀態中之釋放按鈕(4)允許該致動器(3)軸向地運動朝近側端位置,且其中於該不活動狀態中之釋放按鈕(4)允許該致動器(3)軸向地運動朝該近側端位置或朝該遠側端位置。1‧‧‧後面外殼2‧‧‧容器夾具3‧‧‧致動器4‧‧‧釋放按鈕5‧‧‧鎖環6‧‧‧鎖定套筒配置7‧‧‧筆式針100‧‧‧藥物遞送裝置
