A powder container includes an open/close lid that closes an opening partly formed in a container body corresponding to a powder opening of a container receiver; a first restricting portion that, upon attachment of the container body to the container receiver, contacts a contact surface formed upstream of the powder opening to restrict a position of the lid in an open/close operation direction thereof; a flexible sealing member that protrudes from an opening-side edge of an open position, and closes an opening-side portion of a gap between the contact surface and the first restricting portion; and a second restricting portion that, upon detachment of the container body, when a press member restricts movement of the lid, restricts a posture of the sealing member so as to be pressed against an edge portion of the powder opening at a position where the first restricting portion contacts the contact surface.