PURPOSE: To control exactly temp. till the end of the injection system with a simple constitution, by controlling the temp. of a photoresist from the inside of a container in a thermostat to the injection part using a liquid adjusted to a constant temp. with a temp. controller.

CONSTITUTION: A gelatin 7 in a container 8 is controlled to a constant temp. using a liquid 6 adjusted to a constant temp. with a temp. controller 5. A tube 28 is installed from a thermostat 1 through a pump 27, a coating chamber 10, again to the thermostat 1, and the injection tube 11 of the gelatin 7 is installed in the inside of said tube 28 to the coating chamber 10, and a wafer 20 on a chuck 19 is coated with the gelatin 7 to form a coat. When the pump 27 is driven, the liquid in the thermostat 1 is recycled through the tube 28 surrounding the tube 11 to keep the temps. of the gelatin in the container 8 and the gelatin in the tube 11 equal to each other, thus permitting simple and secure control of the injection temp. of the gelatin 7.