A chilled arm that transports a substrate to and from a heating plate for performing a heating process on the substrate is formed with a flow passage pipe therein, and cools the entire holding area thereof opposed to the substrate held by the chilled arm to a predetermined reference temperature by supplying circulating cooling water through the flow passage pipe. Six polyimide heaters are affixed to the holding area to control the temperature of at least a portion of the holding area at a temperature different from the reference temperature. These two temperature control mechanisms intentionally provide a temperature distribution to the holding area to thereby provide an intentional temperature distribution to the substrate before and after the heat treatment by the heating plate. This reduces the nonuniformity of a temperature distribution which typically occurs in the heating plate to accomplish a uniform heat treatment throughout the heat treatment process step.