PURPOSE: To as slipping and the like in a high speed disc rotary system semiconductor manufacturing device with which a gas stream can be controlled perfectly.

CONSTITUTION: The main body 11 has a supporting part 13, to be used for mounting of a wafer 14, and a scattering part 17 which is used to make uniform the heat distribution of the wafer 14, and two or more parts are provided directly under the scattering part 16. Heat sources 15A to 15C, with which each part can be controlled independently, are arranged. Also, the scattering part 16 has a low emissive region 16', which is formed by the material of low emissivity, provided on the region directly under the supporting part 13. As a result, the temperature distribution on the surface of the wafer 14 can be made uniform, and the defects such as slipping and the like can be suppressed to the minimum.