Abstract
This study follows the former paper titled "A genealogical analysis on the block plan of hospital architecture", and analyzes the planning policy of an operating theater in Japanese hospitals from genealogical point. After 50's the discussion concerning dividing clean zone from dirty space has begun, and "the adding vestibule type" and "the independence of instruments' space" has appeared. During 70's and 00's, enthusiastic discussion has been done. At first splitting the traffic of surgical instruments from other has been proposed. In this case, there are two types for the traffic of instruments, the one is clean instruments and the other is dirty ones. These concepts have created "the clean hall type", "the one way type", "the distribution hall type" and "the gathering dirty instruments corridor type". CDC guidelines for operating theater was published in 1999, a quite new concepts for designing operating theatre has started. At present, rational and efficiency facility design is focused, and the new design concept for long time surgical treatment for patients and personnel is pursued.
