A processing apparatus for performing a process on a surface of an object to be processed by applying a high frequency power to an electrode installed in an airtight processing chamber to convert a processing gas introduced therein into a plasma, includes a thermal transfer gas feed pathway for supplying a thermal transfer gas for controlling a temperature of the object to be processed to a minute space between the object to be processed and a holding unit installed on the electrode for attracting and holding the object to be processed through an inner portion of an insulating member disposed under the electrode. A portion of the thermal transfer gas feed pathway, which passes through the inner portion of the insulating member, is formed in a zigzag shape or a spiral shape with respect to a normal direction of a holding surface of the holding unit.