PURPOSE: A helium feed through is provided to stably supply coolant gas to a reaction chamber and improve endurance by using a heat-resistant material and by simply improving the connection structure with a connection unit. CONSTITUTION: The helium feed through is installed in a portion under the reaction chamber to supply coolant gas to the bottom surface of a wafer. A main body(410) is made of a ceramic material and has a gas flow path(430) that has a center portion of a V type whose center is bent. The outer diameter of both side ends of the main body extends further so that a connection unit(700) of an edge part(420) is connected to an extended circumferential portion by a screw(800).
