PROBLEM TO BE SOLVED: To give a diagnosis for equipment/systems in a short time. SOLUTION: This method comprises raw data collection step of collecting, from sensors 201-20nprovided on equipment/systems within a building, primary data (raw data) used for the diagnosis for the equipment/systems via a data collection and recording device 10; diagnostic data formation step of processing the primary data to form secondary data and tertiary data (diagnostic data) used directly for the diagnosis in the field of the building, and diagnostic data presentation step of presenting the diagnostic data to a user U (diagnosing person) in the field. COPYRIGHT: (C)2006,JPO&NCIPI