A disk chucking device is disclosed. In accordance with an embodiment of the present invention, the disk chucking device coupling a disk to a rotor of a motor can include: a housing, which accommodates a boss that is coupled to the rotor; a plurality of chuck pins, which is inserted into the housing such that the chuck pins are protruded to the outside of the housing; an elastic body, which elastically supports an adjacent pair of the chuck pins toward the outside of the housing; a supporting surface, which is formed on an outer circumference of the boss to support a center portion of the elastic body; a guide part, which faces the supporting surface to guide a movement of the elastic body; and a protruding part, which is protruded on a lower end of the guide part toward the boss to support a lower side of the center portion of the elastic body.