A sheet storage apparatus includes a sheet discharge path having a sheet discharge outlet; a stack tray disposed on a downstream side of the sheet discharge outlet; a support device disposed between the sheet discharge outlet and the stack tray to load at least a part of a sheet; a sheet end regulation device for regulating a position of at least one end edge of the sheet supported by the support device; and an aligning transport device disposed in the support device to carry the sheet toward the sheet end regulation device. The aligning transport device includes a friction transport body and a transport body travel device, and the friction transport body has a rotating member rolling along the top surface of the sheet supported by the support device, and the rotating member rotates in a direction crossing the travel direction.