A toner supplying container has a container body having a toner discharge opening, a shutter member, a lever member, and a locking member. The lever member at its closing position causes the elastic portion of the locking member to be elastically deformed to urge the locking member to the locking position. When the container body is mounted on the image-forming machine body, the locking member is displaced to a lock-releasing position, permitting the lever member to be turned from the closing position to the opening position.