Methods: A hot water dishwasher (NP-TR5, Panasonic) was studied for the decontamination of the vessels. The temperature in the dishwasher (DW) was measured with a data logger with ten channels (GL220-UM-801, Graphtec). Soil indicator plate (TOSI, Nichion) and Enterococcus faecalis JCM5803 were used for the decontamination test. 10CFU of E.faecalis were loaded on each test vessels and recovered with phosphate buffer solution after reprocessing. And the solution was cultured on tryptic soy ager at 30°C for 48hrs and then counted. The effectiveness of decontamination was evaluated by hemoglobin indicator(HemoCheck-s, PEREG GmbH). The results were evaluated by color reactions of twelve steps.