A powder feeder includes a plurality of driving rollers with their axial centers horizontal, a cylindrical hopper placed on the driving rollers and rotationally driven, a connection opening formed in the rotating hopper for loading powder therein, a chuck inserted into the connection opening and supported by a support frame, a powder discharge passage interconnecting the inside and outside of the rotating hopper through the chuck, a scooping part continuously formed on an inner surface of the rotating hopper which faces an inner end of the powder discharge passage, and a pressurization passage open to the inside of the rotating hopper for pressurizing the inside of the rotating hopper, the inner end of the powder discharge passage interconnecting the inside and outside of the rotating hopper being open to a location where the powder that has been scooped up by the scooping part falls down.