PURPOSE: To make coating in an uneven shape possible by providing moveable heating member around the outer periphery of a tubular material.

CONSTITUTION: The one end of a metallic tubular material 1 is connected through a blast pipe 7 to the one end of a blower 5. The other end of the metallic tubular material 1 is connected through a blast pipe 7' to a hopper 6 which is fixed to the other end of the blower 5. Around the outer periphery of the tubular material 1 there is provided heating member consisting of high frequency induction heating coil 2 which can be moved along a travelling rail 4. After powder paint thrown into the hopper 6 is supplied to the tubular material 1, electric current is applied to the high frequency induction heating coil 2 to heat partially the tubular material 1, whereby the powder paint is fixed at the heated part. When the movement of the high frequency induction heating coil 2 is controlled properly, the powder paint is fixed partially in thick layer of coating and partially in thin layer of coating, and the coating 9 in the shape of an unevenness is obtained.