A sheet finishing apparatus includes a punch unit to punch a sheet, and a saddle unit to bundle and to fold the sheets. A position and an inclination angle of a puncher are changed according to a skew amount of the sheet, the puncher is controlled to form punch holes in the sheet at positions symmetric with respect to a folding line, and punching is performed so that an interval between the folding line and the punch hole becomes small at the inside of a bundle of the sheets and becomes large at the front cover side.