The invention relates to an applicator (10) for applying a single- or multicomponent fluid, especially a tissue glue, comprising a casing (12) to which at least one reservoir (16) for the fluid can be attached. Said reservoir (16) has an outlet (28) and a piston (20) which is positioned in such a way that it can slide towards said outlet (28). A cocking lever (58) is pivotably mounted on the casing (12). When manually operated, said cocking lever moves a trigger element (54) by which means a spring (46) is stretched to store mechanical energy. The trigger element (54) is coupled with a driving element (66), which when driven by the stored mechanical energy of the spring (46) over an incremental distance moves a pressing element (84), said pressing element acting upon the piston (20) to push it towards the outlet (28) of the reservoir (16).