PURPOSE: To sufficiently degauss the CRT with a degauss coil by devising the degauss coil such that the magnetic field by the degauss coil is not interfered with a magnetic field by a vertical deflection yoke.

CONSTITUTION: A switch SW1 is closed to energize a degauss coil 4 and its magnetic field is used to degauss the CRT. After the degaussing effect is sufficiently obtained, a switch SW2 is closed to supply a current to a vertical deflection yoke 2. During the degaussing by the degauss coil 4, since no current flows to the vertical deflection yoke 2, no magnetic field is generated, the mutual interference is prevented and the sufficient degaussing effect is obtained.