A tubular electrode (215) and a tubular magnet (216) are installed on an external section of a processing furnace (202) for an MMT device. A susceptor (217) for holding a wafer (200) is installed inside a processing chamber (201) of the processing furnace. A gate valve (244) for conveying the wafer into and out of the processing chamber; and a shower head (236) for spraying processing gas in a shower onto the wafer, are installed inside the processing furnace. A high frequency electrode (2) and a heater (3) are installed inside the susceptor (217) with a clearance between them and the walls forming the space. The clearances formed between the walls forming the space in the susceptor and the high frequency electrode and the heater prevent damage to the high frequency electrode and the heater even if a thermal expansion differential occurs between the high frequency electrode, the heater and the susceptor.