The invention relates to a device for the application of a flowable medium, notably a tissue adhesive, comprising at least one reservoir (16) for the medium which presents an outlet (22) from which the medium exits when the medium and/or the reservoir (16) are subjected to pressure. A pressure-generating element (20) acts on the medium and/or the reservoir (16) and is preloaded by means of a preload device (34). Said preload device (34) can be blocked by means of a controllable blocking device (58) which presents a mobile fixing element (54) which in at least one fixing position immobilizes the preload device (34) against movements induced by preloading and for releasing said preload device (34) can be moved out of the at least one fixing position. The invention also provides for a release device (81) for the targeted releasing of the blocking device (58). The release device (81) comprises a release element (82) for temporarily displacing the fixing element (56) from its at least one fixing position.