Technical Problem Provide is a discharge device capable of easily controlling an operation of a plunger at the time of supplying a viscous material to a cylinder and a liquid supply method capable of forming a desired overlap portion.
Solution to Problem The discharge device 10 includes the supply valve 40 which controls the supply of the viscous material M to the cylinder 30, the plunger 50 which applies a pressure to the viscous material supplied to the cylinder, the ball screw 60 which is movable in the same direction as the back-and-forth direction of the plunger, and the motor 120 which is connected to the ball screw through the power transmission mechanism 110, wherein the plunger and the ball screw are not connected.