An injector device for percutaneously injecting biomaterial in the form of particles of different sizes or in the form of paste includes a trocar (12) of generally cylindrical shape presenting a open first end with a sharp edge, the wall of the first end presenting at least one orifice (36, 38) for passing the biomaterial, and a second end (42) that is likewise open; a reservoir (14) for receiving the biomaterial, the reservoir including a part (20) of substantially cylindrical shape having two open ends, the cylindrical part being capable of being inserted at least in a portion of the trocar via the second end thereof; removable plugs for closing both ends of the reservoir; and a piston (16) insertable in the cylindrical part when the plugs are removed, the piston being capable of sliding in the cylindrical part and in the first end of the trocar.