A brake cylinder for pneumatic vehicle brakes, especially for utility vehicles includes a spring brake section for carrying out parking brake actions by way of a brake spring, and a service brake section for carrying out pneumatic service brake actions. The spring brake section and the service brake section are combined in one housing as a structural unit. The housing is subdivided by a piston into two compartments, one compartment of the two being used as the pressure compartment for actuating the service brake section, and the brake spring of the spring section being arranged in the other compartment on the opposite end of the piston. The brake spring acts upon an additional spring piston in the compartment, which can be locked relative to the piston by a pneumatic locking mechanism and can be released therefrom by releasing the locking mechanism. The spring piston is connected to a piston rod directly or via additional elements to actuate the vehicle brake. Once the locking mechanism is released, the brake spring is effective between the two pistons and displaces them relative to each other during a parking brake action. The locking mechanism is configured as a pneumatic coupling.