Disclosed is a vibration damper comprising a cylinder in which a piston rod is guided in an axially movable manner. A first piston is mounted stationarily on the piston rod while a second piston that is equipped with at least one valve disk biased by a spring assembly is mounted on the piston rod so as to be axially movable counter to a force of at least one support spring. The spring assembly is provided with at least one spring plate on which the spring assembly rests. The second piston is retained by a fixing sleeve which supports the at least one spring plate. The structural unit encompassing the fixing sleeve and the at least one spring plate is fitted with an axially effective separating joint for a locking connection inside the structural unit. The entire structural unit can be axially displaced towards the at least one support spring.