Sheet feeding and image forming apparatus

A sheet feeding apparatus which can prevent the changes at the time of installation of a sheet cassette, and deformation and change of the blades after mounting of the sheet cassette regardless of a sheet size is proposed. A movable side regulating plate (315) which is provided in a frame (312) regulates the position in the width direction of the side ends of sheets and is provided with sheet pressing portions (316 and 317) is provided, which press the side ends of the sheets so that the sheets against a fixed side regulating plate (314) are pressed in a biasing manner. do not abut one provided with a recess configuration (316c), stacked against which, when on a sheet stacking plate (313) short sheets by the sheet pressing portion (316) are pressed, upstream ends of the blades is of a bottom end of the sheet pressing portion (316) to a predetermined amount of a Blattzufuhrrichtungsmitte of the sheet pushing portion (316) is formed.