Abstract: Syringe, specifically for use in medicine, comprising a cylinder provided with an opening at its front end, wherein a plunger is disposed for displacement whose plunger rod projects from the rear end of the cylinder, with provisions for fluid-tight attachment or insertion of a needle, specifically an injection needle or a similar aspiration and/or administration element at or into the opening formed at or in the front end of the cylinder. Locking means are associated with the plunger and/or the plunger rod, which may be used to administer the maximum volume of the syringe only once.