Abstract: In a thin-film deposition method, a substrate is placed in a heat chamber having a pressure equal to or higher than an atmospheric pressure, and the substrate is heated in the heat chamber by supplying gas having a temperature higher than a room temperature by forced convection. The heated substrate is transferred from the heat chamber into a deposition chamber which is a vacuum chamber connected to the heat chamber directly or indirectly with a valve interposed therebetween. Then, a thin-film deposition is carried out on the substrate in the deposition chamber at a deposition temperature higher than the room temperature.