In a sheet finisher which receives a sheet from an image forming apparatus, conducts a sheet finishing onto the sheet and feeds out the sheet, the sheet finisher includes: a stacking section which stores temporarily one or more sheets; and a sheet finishing section which conducts the sheet finishing onto the sheet stored in the stacking section. The stacking section having a first guide member which forms a stacking surface to guide the sheet, and a second guide member which faces the first guide member and is spaced apart from the first guide member by a predetermined distance, and is provided obliquely from a horizontal direction, and the stacking surface formed by at least a part of the first guide member, is formed to be curved in a direction perpendicular to a sheet conveyance direction.