An image forming apparatus includes an image forming device, a body, an intermediate transfer unit, a cover, and a guide rail. The body has a bottle housing hole in which a toner bottle is removably inserted. The intermediate transfer unit includes an intermediate transfer belt and a plurality of rollers to drive the intermediate transfer belt and is removably disposed between the image forming device and the bottle housing hole. The intermediate transfer unit and the toner bottle are accessible from a front side of the body. The openable and closable cover is disposed at an inlet-and-outlet port of the bottle housing hole. The guide rail is disposed at a lower side of the bottle housing hole to slidably guide the intermediate transfer unit and has a front-side end extended to a position crossing at least a vertical projection line of the cover on the front side of the body.