PURPOSE: To assure stable operation and inexpensive production by moving a permanent magnet to change the magnetic force on the joint surfaces of a holder and magnetic material thereby attracting or detaching a mask.

CONSTITUTION: A solenoid coil 3 is impulsively excited by a DC power source via lead wires 7 while the mask 1 is brought near to the same. The permanent magnet 4 is preliminarily magnetized so as to move downward by repulsing from the magnetic field of the coil 3 when a driving pulse 8 is inputted to the coil 3. The magnet 4 is therefore moved by the input of the pulse 8 in any position where the permanent magnet exists and thereafter a closed magnetic path consisting of the magnet 4, a yoke 2 and the magnetic material of the mask 1 is formed and the mask 1 is kept attracted by the magnetic field of the magnet 4. A driving pulse 9 is inputted to excite the coil 3 in the case of detaching the mask 1 from the holder. The holder is thus stably operated to surely hold the mask and is inexpensively produced.