Suitable for drying or heat treatment of semiconductor, LCD, electronic products and precision instruments in a dust free environment. Equipped with high temp. heat resistant HEPA filters and designed with horizontal circulation mode. Class 100 cleanliness is achieved at constant temperature. Self-diagnosis functions (abnormal temp. sensing, heater disconnection, auto overheat prevention, SSR short circuit), overheat protector, electric leakage breaker, key lock, etc.