A manufacturing includes forming an insulating layer covering a portion of a first semiconductor layer on a semiconductor substrate, removing a portion of the first semiconductor layer which is not covered with the insulating layer with an etchant to expose a potion of the first main surface, and cleaning the first main surface using a cleaning liquid containing hydrofluoric acid. An etching rate by the etchant to etch the first semiconductor layer is higher than an etching rate by the etchant to etch a first surface layer of the insulating layer, the first surface layer being on the side opposite to the first semiconductor layer. An etching rate by the cleaning liquid to etch a second surface layer of the insulating layer, the second surface layer being on the first semiconductor layer side, is lower than an etching rate by the cleaning liquid to etch the first surface layer.