The invention relates to a injection device, comprising a housing being adapted to receive in its proximal housing portion a container with an injection fluid and to receive in its distal housing portion a dose setting and injection mechanism, wherein the mechanism includes a piston rod (28) being axially displaceable with respect to the housing for dispensing injection fluid from the container, wherein the piston rod (28) has an outer thread (34) and is arranged torque proof with respect to the housing, dose setting means comprising a threaded element, which threaded element has an inner thread being in engagement with the outer thread (34) of the piston rod (28), is designed so that its axial position relative to the housing is changeable and is rotatable relative to the piston rod (28) and relative to the housing during setting of an injection dose, wherein the dose setting means are designed such that the threaded element is held in torque proof manner relative to the piston rod (28) and to the housing during the injection of the beforehand set injection dose in such a manner that the threaded element and the piston rod (28) are axially displaceable together with respect to the housing, wherein the mechanism (26) further comprises holding means (60； 160) being in contact with the piston rod (28) and being designed such that the axial displacement of the piston rod (28) can be substantially immobilized during use of the device except for the dispensing of the injection dose. It is proposed according to the invention that the holding means (60； 160) are axially fixed with respect to the housing.本發明關於一種注射裝置，其包括一殼體，該殼體適於在其近端殼體部分中接納一具備一注射液的容器且適於在其遠端殼體部分中接納一劑量設定及注射機構，其中該機構包含一可相對於該殼體軸向地位移以自該容器施配注射液的活塞桿(28)，其中該活塞桿(28)具有一外螺紋(34)且被設置為相對於該殼體抗扭轉；劑量設定件，其包括一有螺紋元件，該有螺紋元件具有一與該活塞桿(28)之外螺紋(34)接合的內螺紋，該有螺紋元件經設計使得其相對於該殼體的軸向位置係可改變且在一注射劑量之設定期間可相對於該活塞桿(28)及相對於該殼體旋轉，其中該劑量設定件經設計致使該有螺紋元件在事先設定的注射劑量之注射期間以一使該有螺紋元件及該活塞桿(28)可一起相對於該殼體軸向地位移的方式被以相對於該活塞桿(28)及相對於該殼體抗扭轉的方式固持，其中該機構(26)進一步包括固持件(60；160
