A powder feeding mechanism includes: a feeding member, provided under powder, for feeding the powder; and a vibration applying member for applying reciprocating acceleration to the feeding member in a feeding surface direction along a powder feeding surface of the feeding member. Maximum acceleration applied from the vibration applying member to the feeding member in a powder feeding direction is smaller than maximum acceleration applied from the vibration applying member to the feeding member in a direction opposite to the powder feeding direction to feed the powder in the powder feeding direction by the feeding member.