A nozzle insertion member is in a powder container that includes a nozzle insertion opening into which a conveying nozzle is inserted. The nozzle insertion member includes an opening/closing structure to move to an opening position to open the nozzle insertion opening by being pressed by the inserted conveying nozzle, and to a closing position to close the nozzle insertion opening when the conveying nozzle is separated from the nozzle insertion member, and a seal arranged at the nozzle insertion opening and including a through hole into which the conveying nozzle is insertable. The opening/closing structure includes a front cylindrical portion to contact with an inner surface of the through hole, and a slide area formed on another side relative to the front cylindrical portion. W1