Ultra energy saving eco oven with power consumption cut by 50% compared to the conventional model (DN). Highly hermetic bath construction prevents dusts or foreign matters from entering chamber. Time required to attain the highest temperature has been shortened by up to 15 minutes (with no-load, our DN ratio). Shortened wait time and recovery time minimize down time and make work effective. Silicon-free eco oven with Viton(R) fluoroelastomer door packing. (DNE650V/670V/850V) Supports multi-power sources by simply connecting to either 100/120V (DNE650) or 200-240V (DNE670/850). Four-fold overheat preventive functions (automatic overheat prevention, heater room overheat prevention, overheat prevention in the bath, and temperature fuse) assure optimal safety. Equipped with various functions: self-diagnostic, alarm history monitoring, key lock and over current electric leakage breaker. Additional functions such as RS485 communication, temperature output, external alarm and time-up output allow system upgrade based on specific application