Combined service brake and stored-energy brake cylinder having: a) a diaphragm which is arranged in a housing of the service brake cylinder, can be loaded with pressure and delimits a service brake chamber which can be loaded with a service brake pressure on one side and a chamber which accommodates restoring springs on the other side, b) a stored-energy brake piston which is arranged in a housing of the stored-energy brake cylinder, can be actuated by a storage spring, delimits a stored-energy brake chamber on one side and a spring chamber which accommodates a storage spring on the other side, and has a piston rod which carries a venting valve which produces or shuts off a flow connection between the spring chamber and the service brake chamber, characterized in that the venting valve has the following features: c) a piston is provided which carries a valve body and is guided axially displaceably in a cylinder which is formed on the piston rod, d) at least one compression spring which is supported on the piston loads the valve body against a first valve seat on the piston and against a second valve seat on the cylinder, e) the valve body is loaded by the pressure in the spring chamber in a direction which lifts it up from the first valve seat and from the second valve seat, f) the piston is loaded by the pressure in the service brake chamber in a direction which presses the first valve seat against the valve body and lifts the valve body up from the second valve seat, g) a flow connection being produced between the service brake chamber and the spring chamber when the valve body is lifted up from the first valve seat and/or from the second valve seat. a) a diaphragm which is arranged in a housing of the service brake cylinder, can be loaded with pressure and delimits a service brake chamber which can be loaded with a service brake pressure on one side and a chamber which accommodates restoring springs on the other side, b) a stored-energy brake piston which is arranged in a housing of the stored-energy brake cylinder, can be actuated by a storage spring, delimits a stored-energy brake chamber on one side and a spring chamber which accommodates a storage spring on the other side, and has a piston rod which carries a venting valve which produces or shuts off a flow connection between the spring chamber and the service brake chamber, c) a piston is provided which carries a valve body and is guided axially displaceably in a cylinder which is formed on the piston rod, d) at least one compression spring which is supported on the piston loads the valve body against a first valve seat on the piston and against a second valve seat on the cylinder, e) the valve body is loaded by the pressure in the spring chamber in a direction which lifts it up from the first valve seat and from the second valve seat, f) the piston is loaded by the pressure in the service brake chamber in a direction which presses the first valve seat against the valve body and lifts the valve body up from the second valve seat, g) a flow connection being produced between the service brake chamber and the spring chamber when the valve body is lifted up from the first valve seat and/or from the second valve seat.