A sheet loading device, comprising: a housing; a sheet discharge portion that discharges a sheet in a predetermined discharge direction; a sheet loading portion disposed in the housing, on which the sheet discharged from the sheet discharge portion is loaded; a plurality of ribs protruding upward from the sheet loading portion along the discharge direction, each rib having a sloped part (242A1) that tapers downward to an upstream side in the discharge direction; characterized by an actuator including a shaft disposed above the sheet loading portion, the shaft extending in a sheet width direction intersecting the discharge direction, and a contact piece extending from the shaft toward the sheet loading portion, in a position where the ribs are not disposed in the sheet width direction, the contact piece rotating integrally with the shaft when the sheet discharged to the sheet loading portion comes into contact with the contact piece; and a sheet detecting portion capable of detecting, in accordance with the rotation of the contact piece about the shaft, a first state where no sheet is loaded on the sheet loading portion, a second state where one sheet discharged from the sheet discharge portion is loaded on the sheet loading portion, and a third state where sheets as many as a predetermined number of sheets regarded as a full load state are loaded on the sheet loading portion, wherein in the first state, the contact piece is positioned at a stand-by position in which a tip of the contact piece is extended so as to be lower than an upper edge of the rib and wherein the sheet detecting portion includes: a housing that rotatably supports the shaft; a first detection piece that is extended from the shaft in a radial direction of the shaft, and is rotatable integrally with the shaft; a first sheet detecting portion capable of detecting the first state and the second state in accordance with rotation of the first detection piece; a second detection piece that is extended from the shaft in the radial direction of the shaft, and is rotatable integrally with the shaft; and a second sheet detecting portion capable of detecting the third state in accordance with rotation of the second detection piece. a housing; a sheet discharge portion that discharges a sheet in a predetermined discharge direction; a sheet loading portion disposed in the housing, on which the sheet discharged from the sheet discharge portion is loaded; a plurality of ribs protruding upward from the sheet loading portion along the discharge direction, each rib having a sloped part (242A1) that tapers downward to an upstream side in the discharge direction; characterized by an actuator including a shaft disposed above the sheet loading portion, the shaft extending in a sheet width direction intersecting the discharge direction, and a contact piece extending from the shaft toward the sheet loading portion, in a position where the ribs are not disposed in the sheet width direction, the contact piece rotating integrally with the shaft when the sheet discharged to the sheet loading portion comes into contact with the contact piece; and a shaft disposed above the sheet loading portion, the shaft extending in a sheet width direction intersecting the discharge direction, and a contact piece extending from the shaft toward the sheet loading portion, in a position where the ribs are not disposed in the sheet width direction, the contact piece rotating integrally with the shaft when the sheet discharged to the sheet loading portion comes into contact with the contact piece; and a sheet detecting portion capable of detecting, in accordance with the rotation of the contact piece about the shaft, a first state where no sheet is loaded on the sheet loading portion, a second state where one sheet discharged from the sheet discharge portion is loaded on the sheet loading portion, and a third state where sheets as many as a predetermined number of sheets regarded as a full load state are loaded on the sheet loading portion, wherein in the first state, the contact piece is positioned at a stand-by position in which a tip of the contact piece is extended so as to be lower than an upper edge of the rib and wherein the sheet detecting portion includes: a housing that rotatably supports the shaft; a first detection piece that is extended from the shaft in a radial direction of the shaft, and is rotatable integrally with the shaft; a first sheet detecting portion capable of detecting the first state and the second state in accordance with rotation of the first detection piece; a second detection piece that is extended from the shaft in the radial direction of the shaft, and is rotatable integrally with the shaft; and a second sheet detecting portion capable of detecting the third state in accordance with rotation of the second detection piece. a housing that rotatably supports the shaft; a first detection piece that is extended from the shaft in a radial direction of the shaft, and is rotatable integrally with the shaft; a first sheet detecting portion capable of detecting the first state and the second state in accordance with rotation of the first detection piece; a second detection piece that is extended from the shaft in the radial direction of the shaft, and is rotatable integrally with the shaft; and a second sheet detecting portion capable of detecting the third state in accordance with rotation of the second detection piece.