A syringe having a dispensing element (20) and having a mounting element (2), wherein the dispensing element (20) has a dispensing sleeve (21) and a leaf spring system (3), wherein the mounting element (2) has a syringe body (17), and an injection needle (16) is formed on one end on the syringe body (17) and a detent-engagement flange (19) is formed on the other end, wherein, in the syringe body (17), there is arranged a movable stopper (18), wherein the leaf spring system (3) comprises a piston (6) and a spiral spring (5) arranged around the piston (6), wherein the piston (6) can be slid into the dispensing sleeve (21), and the spiral spring (6) is arranged between a leaf spring base (22) and a spiral spring abutment, wherein the piston (6) abuts against the stopper (18), wherein the dispensing sleeve (21) has a guide duct and the dispensing sleeve (21) comprises a first locking means (7) and a second locking means (9), wherein the detent-engagement flange (19) is movable in the guide duct and is fixable and releasable at the first locking means (7) or the second locking means (9).