To improve a response when a temperature is raised even while making a temperature distribution on an upper surface of a hot plate uniform.

The heat-treating apparatus mounts a substrate W on a hot plate 1, and heat-treats it. In this case, a heat pipe 7 is embedded in the plate 1, and a cooling groove 9 is provided. Thus, a thermal capacity of the plate 1 can be reduced, and a response when the temperature of the plate 1 is raised can be improved while holding the distribution of the upper surface of the plate 1 uniform. Particularly, since the groove 9 is arranged on the plate 1 having small thermal capacity, a response when the temperature is lowered can be extremely enhanced.