Patent ID: 7556252

Claim:
A sheet post-processing apparatus comprising: a processing tray on which a sheaf of sheets is made, the processing tray further comprising; a mounting area on which a sheet to be stapled is stacked; a flexible portion which is formed integrally with the mounting area and at the same level as the upper surface of the mounting area, along the edge of the mounting area of the side to staple the sheaf of sheets, and is bent easier than the mounting area in the direction of the thickness of the sheaf of sheets toward the mounting area; and an edge holding part which extends to the stapler further than the flexible portion, and supports the edge of a sheet stacked on the mounting area; and a stapler which staples the sheaf of sheets, the stapler further comprising: a fixed part which is provided at a position deviated from the upper surface of the mounting area to an opposite side of the mounting area, and closer to the mounting area than the edge holding part; and an arm which is provided at a position to hold the edge of the sheaf of sheets toward the fixed part, and is rotationally moved in the direction of stacking the sheaf of sheets, wherein the flexible portion is made thinner than the mounting area in the direction of stacking the sheaf of sheets.