An injection device having a housing, a dose setting member being operable to set a desired dose, a piston rod adapted to cooperate with a piston to cause a set dose to be expelled, and a mode locking member. The mode locking member is adapted to be in a first extreme position and in a second extreme position. When the mode locking member is in the first extreme position the piston rod is prevented from cooperating with the piston, and when the mode locking member is in the second extreme position the dose setting member is prevented from being operated to set a dose. The mode locking member is adapted to be in the first extreme position during dose setting and the second extreme position during injection of a set dose.