Manual injection device comprising a lower body (1) receiving a reservoir (S) containing fluid to be injected, a piston (P) and a needle (A), an upper body (2) axially displaceable relative to said lower body (1) during actuation, said upper body (2) comprising a piston rod (TP) cooperating with said piston (P) during the injection to move it in the tank S, an actuator sleeve (10) comprising a contact end (11) intended to come into contact with the body of the user, said actuator sleeve (10) being displaceable with respect to said lower body (1) between projected positions, in which said actuator sleeve (10) makes at least partially protruding from said lower body (1), and an actuating position, wherein said actuator sleeve (10) is axially displaced inwardly of said lower body (1), said actuator sleeve (10) being in a pre first projected position before actuation of the manual injection device and in a second projected position after actuation of the manual injection device, said actuator sleeve (10) defining with said lower body (1), or with any element integral with said lower body ( 1), such as a tank support, a stitching lock, and said piston rod (TP) defines with said tank (S), or with any integral element of said tank (S), such as a tank support or such that said lower body (1), an injection lock, the force required to actuate said tapping lock being less than the force required to actuate said injection lock, so that said tapping lock is actuated before said injection lock. Dispositif d'injection manuelle comportant un corps inférieur (1) recevant un réservoir (S) contenant du produit fluide à injecter, un piston (P) et une aiguille (A), un corps supérieur (2) axialement déplaçable par rapport audit corps inférieur (1) lors de l'actionnement, ledit corps supérieur (2) comportant une tige de piston (TP) coopérant avec ledit piston (P) lors de l'injection pour le déplacer dans le réservoir S, un manchon actionneur (10) comportant une extrémité de conta
