Post-processing apparatus and image forming apparatus

An image forming apparatus comprising:

• a post-processing apparatus;
• and a printing portion configured to execute a print job and to feed a printed paper sheet to the post-processing apparatus, wherein
• the post-processing apparatus includes:
• a processing tray configured to stack thereon a paper sheet to be processed by stapling processing;
• a conveyance portion configured to convey the paper sheet to the processing tray;
• a staple unit having an automatic mode and a manual mode as processing modes for the stapling processing, the staple unit being configured to, in the automatic mode, execute the stapling processing for a paper sheet conveyed to the processing tray by the conveyance portion, and in the manual mode, execute the stapling processing for a paper sheet stacked on the processing tray by a user;
• an operation portion configured to receive an operation for switching between the automatic mode and the manual mode;
• a mode switching portion configured to perform switching between the automatic mode and the manual mode in response to an operation on the operation portion;
• a cover attached in an openable and closable manner so as to cover the operation portion when the cover is closed and expose the operation portion when the cover is opened;
• and
• an open/close detection portion configured to detect whether the cover is opened or closed, wherein
• while the open/close detection portion is detecting that the cover is opened, when the operation portion has received an operation for switching to the manual mode, the mode switching portion switches the automatic mode to the manual mode.