Abstract: The invention concerns a device for automatically injecting injection liquids, comprising an axially divided housing, whereof the parts can be removably assembled. In a first part of the housing (13) is guided an axially mobile pressure pin (14) which can be driven in against a force accumulator (15), which can be locked once it has been driven in and can come out when the force accumulator (15) is released. In a second part of the housing (1) are arranged, axially mobile, an injection needle (4) maintained in a needle guide (5) and an ampoule (3). Said injection needle (4) maintained in the needle guide (5) can be axially mobile, relative to the ampoule (3), and has, on its side facing the ampoule (3), a perforation part (23) designed to perforate the ampoule (3). The second part of the housing (1) can be closed with a top (11) at its open end facing the first part of the housing (13).