A deflection yoke of a cathode ray tube apparatus comprises a pair of saddle-type horizontal deflection coils located symmetrically with respect to a central axis and substantially in the shape of a truncated pyramid. A magnetic core substantially in the shape of a truncated cone is located coaxially around the horizontal deflection coils, and a pair of vertical deflection coils are wound on the magnetic core. A relation between a space vf between a large-diameter end portion of the magnetic core and each of the horizontal deflection coils and a space vr between a small-diameter end portion of the magnetic core and each of the horizontal deflection coils, with respect to the direction of a vertical axis perpendicular to the central axis, is given by vf≧vr.