A substrate processing apparatus including lift pins for lifting the substrate capable of moving up and down, a heating plate with holes through which the lift pins protrude and sink to a surface facing the substrate, a lid placed above the heating plate capable of moving up and down, a first inert gas introducing mechanism introducing a first inert gas to the inside portion of the lid and a second inert gas introducing mechanism introducing a second inert gas onto the surface of the heating plate through the holes. With such configuration, the inert gas can be introduced to both sides, the front side and the rear side, of the substrate, and oxygen is prevented from being forced to come around to the surface of the substrate from the rear side thereof. As a result, oxidation of the substrate can be prevented effectively.