A dual clutch device comprising: a first clutch comprising a first plate for connecting and disconnecting the transmission of power from an engine to a first transmission input shaft; a second clutch comprising a second plate for connecting and disconnecting the transmission of power from the engine to a second transmission input shaft; a first piston configured to apply the first clutch by pressing the first plate by means of a hydraulic pressure supplied into a first hydraulic pressure chamber and release the first clutch by being moved away from the first plate by a first spring accommodated in a first hydraulic pressure canceling chamber; a second piston configured to apply the second clutch by pressing the second plate by means of a hydraulic pressure supplied into a second hydraulic pressure chamber and release the second clutch by being moved away from the second plate by a second spring accommodated in a second hydraulic pressure canceling chamber; a first supply line (43, 50) for supplying a hydraulic pressure into the first hydraulic pressure chamber and the second hydraulic pressure canceling chamber; and a second supply line (45, 51) for supplying a hydraulic pressure into the second hydraulic pressure chamber and the first hydraulic pressure canceling chamber; characterised by a first opening-closing valve, which is provided on the first supply line, and which is configured to allow or cut off the supply of a hydraulic pressure into the first hydraulic pressure chamber and the second hydraulic pressure canceling chamber; and a second opening-closing valve, which is provided on the second supply line, and which is configured to allow or cut off the supply of a hydraulic pressure into the second hydraulic pressure chamber and the first hydraulic pressure canceling chamber. a first clutch comprising a first plate for connecting and disconnecting the transmission of power from an engine to a first transmission input shaft; a second clutch comprising a second plate for connecting and disconnecting the transmission of power from the engine to a second transmission input shaft; a first piston configured to apply the first clutch by pressing the first plate by means of a hydraulic pressure supplied into a first hydraulic pressure chamber and release the first clutch by being moved away from the first plate by a first spring accommodated in a first hydraulic pressure canceling chamber; a second piston configured to apply the second clutch by pressing the second plate by means of a hydraulic pressure supplied into a second hydraulic pressure chamber and release the second clutch by being moved away from the second plate by a second spring accommodated in a second hydraulic pressure canceling chamber; a first supply line (43, 50) for supplying a hydraulic pressure into the first hydraulic pressure chamber and the second hydraulic pressure canceling chamber; and a second supply line (45, 51) for supplying a hydraulic pressure into the second hydraulic pressure chamber and the first hydraulic pressure canceling chamber; characterised by a first opening-closing valve, which is provided on the first supply line, and which is configured to allow or cut off the supply of a hydraulic pressure into the first hydraulic pressure chamber and the second hydraulic pressure canceling chamber; and a second opening-closing valve, which is provided on the second supply line, and which is configured to allow or cut off the supply of a hydraulic pressure into the second hydraulic pressure chamber and the first hydraulic pressure canceling chamber.