A manual injection device having a lower body (1) for a reservoir (S), a piston (P) and a needle (A)； a movable upper body (2) including a piston rod (TP)； and an actuator sleeve (10) including a contact end (11) and movable relative to the lower body between projecting positions and an actuated position. The actuator sleeve (10) is in a first projecting position before the manual injection device is actuated, and in a second projecting position after it is actuated. The actuator sleeve co-operates with the lower body (1) or with any element secured to the lower body to define a pricking lock. The piston rod (TP) co-operates with the reservoir or with an element secured to the reservoir to define an injection lock. The force for actuating the pricking lock is less than the force for actuating the injection lock, such that the pricking lock is actuated first.
