A sheet cassette includes a first trailing edge regulator integrally formed with a cassette frame to regulate a position of a trailing edge of a first sized sheet in a feeding direction, and a second trailing edge regulator integrally formed with the cassette frame to regulate a position of a trailing edge of a sheet of a second size stored in the cassette frame in the feeding direction. A pair of side edge regulation members regulate positions of side edges of the sheet of the first size stored in the cassette frame in the width direction at a first position and regulate positions of side edges of the sheet of the second size stored in the cassette frame in the width direction at a second position.