To facilitate taking-out of a sheet discharged to a stacker part.

This sheet loading device includes the stacker part 500 loading the sheet P, a conveyor belt conveying the sheet P to the stacker part, a lift up member lifting up the sheet P loaded on a stack tray 501 of the stacker part 500 from the stack tray 501, and a lift up mechanism raising and lowering the lift up member. The sheet P to be next conveyed on the stack tray 501 by the conveyor belt is conveyed under the previously conveyed sheet P during lifting up the sheet P by the lift up mechanism, the lift up member is lowered by the lift up mechanism after conveyance, and then the lift up member is retreated to load the sheet on the stack tray.