A powder conveying device, including: a powder conveying path including a curved portion; and a conveying screw, wherein the conveying screw is disposed in the powder conveying path, and includes: a rotation axis portion having flexibility; and a blade portion, where the blade portion is helically formed on an outer periphery of the rotation axis portion, and is configured to convey a powder, wherein the conveying screw includes a conveying screw curved portion located in the curved portion of the powder conveying path, and wherein at least a surface of the blade portion of the conveying screw curved portion includes a slipping layer containing a silicon-containing compound.