Abstract: A syringe for the measured filling of a container, such as a bottle or the like, particularly for use on rotary-head filling machines, of the type including a valve means (11) having a cylinder body and arranged to selectively communicate an inlet conduit (5) and an outlet conduit (6) with a cylinder chamber (2) in which a double-acting piston (7) is slidably received, wherein during the cleaning and/or sterilizing of the syringe, both said valve means (11) and piston (7) are positioned within a widening (4) in the cylinder chamber (2) such that pressurized liquid or steam from the inlet conduit (5) will impinge upon and sweep all over the inner wall of cylinder chamber (2), the surface of the valve (11), the piston (7) and the associated portion of piston rod (8) extending inside the cylinder (2), with liquid or steam also flowing through a valve passage (12) in valve means (11).