A wet etching method according to the present disclosure includes rotating a substrate, supplying an etching chemical liquid to a first surface (a surface on which a device is formed) of the rotating substrate, and supplying an etching inhibiting liquid (DIW) to a second surface (a surface on which no device is formed) of the substrate while supplying the chemical liquid to the substrate. The etching inhibiting liquid wraps around the first surface through an edge of the substrate and reaches a first region extending from the edge of the substrate on the peripheral edge portion of the first surface to a first radial position located radially inward from the edge on the first surface. As a result, bevel etching of an upper layer of a substrate on which a film having two layers is formed may be satisfactorily performed.