<p><P>PROBLEM TO BE SOLVED: To provide a plant equipment state management method for improving the accuracy of information showing the opening/closing state of a manual valve installed in a plant. <P>SOLUTION: In a plant equipment state management method, operation instruction information read from a plant equipment state management device 9 is input to a portable terminal 16, and displayed at the portable terminal 16. A manual valve 17 whose opening/closing state should be checked is confirmed by an operator. The equipment ID information of the manual valve 17 is read from an RFID tag 18 of the manual valve 17 by the portable terminal 16. When the manual valve 17 is a manual valve to be operated, the manual valve 17 is put in a predetermined full closing state by the operator, and information showing the full closing state is input to the portable terminal 16. When the operation result of the manual valve 17 is coincident with the operation instruction content, information showing the operation result is transmitted to the plant equipment state management device 9. The display information of piping instrumentation diagram information to which the information showing the operation result has been added is created and displayed by the plant equipment state management device 9. <P>COPYRIGHT: (C)2013,JPO&INPIT</p>
