A method for treating a substrate includes a substrate treating step of treating the substrate by dispensing a treating liquid onto the substrate while rotating the substrate supported on a support plate in a processing space of a processing vessel and a vessel cleaning step of cleaning the processing vessel by dispensing a cleaning solution onto a jig while rotating the jig supported on the support plate. In the substrate treating step, the substrate is clamped to the support plate by a first vacuum pressure applied to the substrate. The vessel cleaning step includes a first clamping step of clamping the jig to the support plate by applying a second vacuum pressure to the jig. The first vacuum pressure and the second vacuum pressure are different from each other.