An injection apparatus (1) has a housing (2), an central longitudinal axis (50), an operating element (6) and a dosing element (18) held rotatably and fixedly in the direction of the central longitudinal axis (50) in the housing (2). The operating element (6), in a first position (51) for setting an amount of injection liquid to be expelled, is mounted such that it can rotate relative to the housing (2) and is connected, via a first coupling (16), to the dosing element (18) for conjoint rotation. In a second position (52) for expelling an amount of injection liquid to be expelled, the operating element (6) is connected, via a second coupling (20), to the housing (2) for conjoint rotation and such that it can rotate relative to the dosing element (18). A first detent mechanism (35) operates between the operating element (6) and the housing (2) and functions only when the operating element (6) is in the first position (51) as the amount of injection liquid to be expelled is set. A second detent mechanism (62) operates between the operating element (6) and the dosing element (18) and functions only when the operating element (6) is in the second position (52) as the amount of injection liquid to be expelled is expelled.
