An image forming apparatus includes an image carrying member unit, a development device, a developer collection mechanism and a unit support tray. The developer collection mechanism is arranged on a downstream side in a first direction where the development device and the image carrying member unit are fitted into the main body of the image forming apparatus and the toner discharge portion of the image carrying member unit is coupled to the developer collection mechanism. The unit support tray is provided such that the unit support tray can be moved horizontally in the first direction and a second direction where the development device and the image carrying member unit are removed from the main body of the image forming apparatus; the unit support tray is moved in the first or second direction such that the toner discharge portion and the developer collection mechanism are coupled or the coupling is cancelled.