To provide a parking brake device capable of restraining heat slack of parking brake force.

A tie rod 12 is fixed to a fixation part 13 provided on a radial directional side of a disk rotor 10 of a support member 4b1 of a second brake caliper 4b. The second brake caliper 4b receives the heat from the disk rotor 10, and the support member 4b1 is expanded in the sliding direction of the piston 8 by the heat, and is shrunk by the radiation of the heat. Since a coefficient of thermal expansion of the brake caliper 4b is larger than that of the tie rod 12, a shrinkage amount of the support member 4b1 is larger than that of the tie rod 12. Therefore, a claw part 4b2 of the support member 4b1 is displaced in a direction for pushing an outer pad 9b by the shrinkage of the second brake caliper 4b, and the outer pad 9b pushes the disk rotor 10 to generate the parking brake force. Thereby, the heat slack of the parking brake can be restrained.