PURPOSE: To facilitate a wiring process and to freely choose coils of various types as required with regard to a screen rotation preventing coil to be adopted for a computer display device.

CONSTITUTION: Wire rods are wound around specific coil bobbins 4, 5, 6. A deflection yoke 2 is inserted in the coil bobbins 4, 5, 6, which are held at specific holding positions so that the display screen side peripheral part 3 of the deflection yoke 2 is surrounded thereby.