A cathode device includes a rotation plate to which a magnetic circuit is fixed, a rotation mechanism including a rotation shaft that rotates the rotation plate when receiving power from a motor, and a linear motion parallel link mechanism. The parallel link mechanism includes an end effector, six links each having a distal end and a proximal end, and three linear motion mechanisms. The end effector rotationally supports the rotation shaft, the distal ends of the links are connected to the end effector, the links radially extend from the end effector, and the linear motion mechanisms move the proximal ends of adjacent two of the links in one direction when receiving power from respective linear actuators. A controller controls a change in position of the rotation shaft performed by a cooperative operation of the linear actuators, and controls rotation of the rotation shaft operated by the motor.