To provide a liquid material supply unit and its method capable of using a liquid material in a material supply container up, and capable of preventing variation in the property of the liquid material, the interfusion of a bubble, and the like.

In a liquid material supply unit, a resist supply bottle 3 containing resist 2 for use as a liquid material and a resist discharge pump 12 are connected to each other via piping 101A and 101C. In the liquid material supply unit, there are provided a tank 10 and air 5 for use as an indirect pressurization means for carrying out the indirect pressurization of the resist 2 by pressurizing the inside of the bottle 3 from the outside, the air 5 for use as direct pressurization means for directly pressurizing the resist 2 in the bottle 3, and a buffer bottle 10 interposed in between the piping 101A and the piping 101C for once allowing the resist 2 sent out from the bottle 3 to be accumulated therein. The management of the amount of the resist 2 in the buffer bottle 10 makes it possible to continue the sequential sending of the resist 2 in the bottle 3, and to use the resist 2 up.