To provide a member having excellent heat radiation characteristic and strong heat resistance by mixing ceramic and metal, and changing the ratio of the ceramic and the metal in the thickness direction.

In the case of using a roller of a rotary anode type X-ray tube as a material to be sprayed for example, a rotor 41 is rotated, and plasma flame 32 is generated from a plasma spraying gun 31, and the plasma spraying gun 31 is reciprocated in the longitudinal direction of the rotor 41 once so as to heat the rotor 41. Then, only a metal material s supplied to the plasma flame, and the plasma spraying gun 31 is reciprocated once so as to form a surface of the rotor 41 with a film of the metal material. The ceramic material and the metal material at 3:7 in weight ratio are supplied to the plasma flame 32 at the same time, and the plasma spraying gun 31 is reciprocated once. Thereafter, the similar operation is performed at 1:1, 7:3 in weight ratio. Finally, a film made of the only ceramic is formed. A film having thickness at several 10 μm to 100 μm over the whole is thereby formed.