1. The Ergonomic Design for Maximizing Operator's Safety and Convenience. It is very convenient to operate and control the sterilizer by one touching the graphic designed button easily and able to monitor the cycle progressing in real time on the large color touch screen. The door moves up and down smoothly without any physical force by adopting the automatic vertical sliding system, therefore the large volume sterilizing is much more safe and convenient than the hinged door type. Moreover it has a advantage of saving the required space to install the sterilizer. The automatic sliding door is divided to the single door type and double door type, the advantage of double door is that the risk of recontamination after sterilization can be removed because the sterilized loads can be taken out in the clean area. The double door type sterilizer is designed to load the items to be sterilized in the chamber through the front door in the loading area and unload items sterilized through the rear door in the clean area in general. The two areas should be separated and blocked completely by the bio-seal device for preventing recontamination after sterilization, and doors are controlled automatically not to be opened at the same time, therefore the front door keeps close during the rear door open or operate in reverse naturally.