To provide an electric parking brake device for a vehicle and its abnormality detecting method for appropriately detecting an abnormality of cable breakage.

The electric parking brake device mounted to the vehicle comprises a computing means for computing a target braking force corresponding to a slope gradient in the present position of one's own vehicle; a tension generating means for generating cable tension for generating the target braking force to a parking brake cable; a determining means for determining whether the own vehicle is moving; and a cable abnormality detecting means for detecting the abnormality of the parking brake cable. If the own vehicle is moving when generating first cable tension for generating the target braking force, the tension generating means generates second cable tension which is double the first cable tension. The cable abnormality detecting means determines that an abnormality has occurred at the parking brake cable if the own vehicle is not moving when the tension generating means has generated the second cable tension.