Image forming apparatus with guide mechanism for image writer

An image forming apparatus includes an apparatus housing having an opening and closing door, an attaching body, an image writer, and a guide mechanism. The guide mechanism moves the image writer in conjunction with opening and closing of the opening and closing door, guides the image writer to a write position upon closing the opening and closing door, and guides the image writer to a retracted position upon opening the opening and closing door. The guide mechanism has a first guide mechanism that moves the image writer along a first guide portion provided in the attaching body while the opening and closing door moves from the close position to an intermediate position, and a second guide mechanism that guides the image writer along a second guide portion provided in the apparatus housing while the opening and closing door moves from the intermediate position to the open position.