An accommodating vessel, which is detachably attached to a vessel receiving part of a casing of an image forming device to accommodate an image forming material, the accommodating vessel including: a vessel main body that includes a tubular part; a cover member that includes a fitted part; at least one positioned protrusion; and at least one positioned positioning protrusion, wherein the at least one positioned protrusion includes: a guide protrusion that extends in a rotating direction of the cover member; and a plurality of rotation stop protrusions that extends in opposite directions to each other relative to the guide protrusion along a pushing and pulling direction of the cover member, and Wherein the positioning protrusion includes a stop wall that abuts on the guide protrusion and the plurality of rotation stop protrusions of the at least one positioned protrusion to be stopped.