A friction brake device for a vehicle comprising: a hydraulic brake unit (38, 40, 34) including a piston member (30; 200) that is configured to be movable by an action of brake fluid pressure and to press a friction member by advancement; an electric brake unit (68, 64, 60; 68, 64, 220) including a nut member (60; 220) that is configured to be relatively movable in a piston movement direction with respect to the piston member (30; 200) by a motor and to press the piston member (30; 200) by advancement, and configured such that a position of the nut member (60; 220) is maintained with respect to the motor when the motor is not in operation; a piston return mechanism including a biasing member (106; 210) that is arranged so as to make biasing force, oriented in a retreat direction, elastically act on the piston member (30; 200) in accordance with an advancement amount of the piston member (30; 200) from a movement start position with respect to the nut member (60; 220), the movement start position of the piston member (30; 200) being determined by the position at which the nut member (60; 220) is maintained, and the advancement amount being provided by an action of the hydraulic brake unit (38, 40, 34); and a controller for controlling the motor, wherein the controller determines whether an adjustment permission condition associated with a wear amount of the friction member is satisfied, and characterized in that when the adjustment permission condition is satisfied, the controller makes a request of a relative position adjustment of the nut member (60; 220) with respect to the piston member (30; 200) by the motor, the controller determines whether an adjustment execution condition that is based on a vehicle state is satisfied, and when the request of the relative position adjustment is made and when the adjustment execution condition is satisfied, the controller executes the relative position adjustment, the relative position adjustment includes updating the maintained position of the nut member (60; 220). a hydraulic brake unit (38, 40, 34) including a piston member (30; 200) that is configured to be movable by an action of brake fluid pressure and to press a friction member by advancement; an electric brake unit (68, 64, 60; 68, 64, 220) including a nut member (60; 220) that is configured to be relatively movable in a piston movement direction with respect to the piston member (30; 200) by a motor and to press the piston member (30; 200) by advancement, and configured such that a position of the nut member (60; 220) is maintained with respect to the motor when the motor is not in operation; a piston return mechanism including a biasing member (106; 210) that is arranged so as to make biasing force, oriented in a retreat direction, elastically act on the piston member (30; 200) in accordance with an advancement amount of the piston member (30; 200) from a movement start position with respect to the nut member (60; 220), the movement start position of the piston member (30; 200) being determined by the position at which the nut member (60; 220) is maintained, and the advancement amount being provided by an action of the hydraulic brake unit (38, 40, 34); and a controller for controlling the motor, wherein the controller determines whether an adjustment permission condition associated with a wear amount of the friction member is satisfied, and characterized in that when the adjustment permission condition is satisfied, the controller makes a request of a relative position adjustment of the nut member (60; 220) with respect to the piston member (30; 200) by the motor, the controller determines whether an adjustment execution condition that is based on a vehicle state is satisfied, and when the request of the relative position adjustment is made and when the adjustment execution condition is satisfied, the controller executes the relative position adjustment, the relative position adjustment includes updating the maintained position of the nut member (60; 220).