A base frame 1 is such as to be fixedly provided on a body so that a parking brake device 2 is provided thereon which causes a brake applying portion of a parking brake to apply the brake and release the brake so applied, a base frame main body la is molded into an integral unit, a parking device mounting portion 10A where the parking brake device 2 is mounted is formed on one side A of the base frame man body 1a, and a gearshift device mounting portion 10B where a gearshift device of a transmission is provided is formed on the other side B thereof.