An apparatus evaluates a substrate mounting device adapted to hold a target substrate placed on a mounting surface and to control a temperature of the target substrate. The apparatus includes an evacuatable airtightly sealed chamber accommodating therein the substrate mounting device, a heat source, arranged in a facing relationship with the mounting surface, for irradiating infrared light. The apparatus further includes an evaluation-purpose substrate adapted to be mounted on the mounting surface in place of the target substrate, the evaluation-purpose substrate being made of an infrared light absorbing material, and having a unit for measuring temperatures at plural sites on a surface and/or inside of the substrate.