A powder conveying device includes an inflow portion, a discharge portion, and a conveying screw. Powder flows into the inflow portion from outside of the powder conveying device. The powder flows out from the discharge portion to the outside of the powder conveying device. The conveying screw includes a shaft and conveys the powder from the inflow portion to the discharge portion in a conveying direction. A surface portion of the shaft at at least one of an upstream end or a downstream end of the shaft in the conveying direction, in at least one of the inflow portion or the discharge portion has a lower friction with the powder than another surface portion of the shaft at a position other than the at least one of the upstream end or the downstream end.