Abstract: A toner supply container comprises a container body accommodating toner. The container body is detachably mounted from above into a machine body of an image forming machine along a first guide member and a second guide member provided with a predetermined spacing in the machine body. The toner supply container includes a first locking mechanism disposed in one end portion of the container body, and a second locking mechanism disposed in the other end portion of the container body. The first locking mechanism includes an engagement claw to be engaged with an engagement stop portion provided in the first guide member when the container body is located at a mounting position, and an unlocking lever for releasing engagement between the engagement claw and the engagement stop portion.