Abstract: A medium reservoir (10) can be inserted from the outside through an insertion opening (24) into the substantially closed casing (6) of a discharge apparatus (1) comprising two actuating units (4, 5) displaceable against one another and can be secured by a mounting support (20) with a snap connection (27) in such a way that it is located in its operating position. Thus, all the components of the discharge apparatus (1) can be preassembled. Subsequently the filled medium reservoir 910) is inserted in an automated operation and through the introduction of a pump piston (11) it can be simultaneously closed or connected to a discharge opening (14).