A side bodyshell of a railcar includes: an outside plate including a window opening; horizontal frames arranged below the window opening and joined to the outside plate; and a vertical frame crossing the horizontal frames in a manner to pass over a pier panel, which is lateral to the window opening. The vertical frame includes: a first flange joined to the outside plate at the pier panel; and a second flange spaced apart from the outside plate below the first flange such that a step is formed between the first flange and the second flange, the second flange being joined to the horizontal frames.