An image forming apparatus includes a main body, a post-printing processing device, and a paper exit part. The main body forms an image on paper. The post-printing processing device is located above the main body and performs post-printing processing on paper. The paper exit part is located on a side surface of the post-printing processing device. Paper is ejected to the paper exit part. The post-printing processing device includes a paper inlet port and a conveyance device. The paper inlet port is located in a rear part of a lower surface of the post-printing processing device. The conveyance device conveys paper conveyed via the paper inlet port into the post-printing processing device in a forward direction thereof to a paper loading tray and conveys the paper therefrom leftward to eject the paper to the paper exit part located on the left side of the post-printing processing device.