An image forming apparatus includes an image bearer; a cleaning unit configured to remove waste toner on the image bearer; a waste toner container configured to be detachably attached to the image forming apparatus and to store the waste toner removed by the cleaning device; and a support member configured to support the waste toner container. The support member is provided with a guide unit thereon that guides the waste toner container in attachment and detachment directions, the guide unit includes a side guide plate that guides each of sides of the waste toner container in the attachment and detachment directions, a guide plate arranged on entrance side of the side guide plate in the attachment direction of the waste toner container, and the guide plate includes an inclined guide surface that guides the waste toner container onto the support member.