PURPOSE: To discharge powder/grain stored in a hopper by the uniform, continuous and stable fixed volume without requiring manpower in a continuous fixed volume supply device of the powder/grain.

CONSTITUTION: A discharge device 40 has a motor 71 and a screw 72 which is rotated by a motor shaft of this motor 7 and sends out powder/grain 20 received in a hopper 30 toward a hopper discharge port 32. The screw 72 has a screw shaft 75 rotated by the motor shaft and a screw blade 76 formed in a spiral shape around this screw shaft 75, and the sending-out volume per pitch of the screw blade 76 is made gradually increasable in the sending-out direction of the powder/grain 20.