Quantity of steam consumed mainly by steam sterilizers were measured. Impurities in steam were also observed by installing steam sterilizers.1) Steam consumption in the central sterile supply department per day was 6% of steam for processes in the whole hospital. 25% of steam consumption in the central supply department was heat loss. Steam consumption marked the highest during the operating time of water sterilized-distillers amongst other equipment. Steam consumption by steam sterilizers marked the highest during a pre-heating time for a jacket. This value should be taken into consideration in designing a steam pipe line or bolier capacity. The hourly steam consumption was only one third of the highest other than that of the pre-heating time.2) Alkalinity (CaCO_3), hardness, SO_4^<3->, PO_4^<3->, and pH showed standard value. The degree of contaimination of the steam filter element was also observed 6th months after installation.The filter element was obviosuly contaminated by impurities in steam. Steam filters were quite effective in removing impurities in steam.3)Electron microscope and X-ray analysis proved to be more reliable than normal chemical analysis in analising elements of stains placed on the stainless steal bar by impurities in steam.