A hydrophobization treatment apparatus includes a cooling device which cools a substrate, a light irradiation device which irradiates thermal radiation light from light sources onto front surface of the substrate, a gas supply device which supplies hydrophobization-treatment gas to the substrate, an exhaust device which exhausts the gas, a lifting device which moves the substrate such that the lifting device raises and lowers the substrate between the cooling device and light sources, and a control device which has circuitry to control the light irradiation device, the gas supply device, the exhaust device and the lifting device. The circuitry of the control device executes first gas supply control to discharge and exhaust the gas into and from the space between the gas container and substrate, and after the first control, second gas supply control to discharge and exhaust the gas into and from the space between the gas container and substrate.