A detachable unit to be attached to a unit-receiving apparatus includes a unit body, a rotary member, an urging member urging the rotary member toward a downstream side in a detachable-unit-attaching direction, a contact-receiving portion provided on the rotary member, first and second support-receiving portions provided at respective ends of the rotary member, first and second supports provided at respective positions of the unit body corresponding to the positions of the first and second support-receiving portions, and first and second rotary support members provided between the first support-receiving portion and the first support and between the second support-receiving portion and the second support, respectively, and supporting the respective ends of the rotary member such that the rotary member is rotatable. The first and second rotary support members are supported in such a manner as to be movable in a detachable-unit-attaching-and-detaching direction.