A portable operation support device for supporting an operation to each facility installed in a plant, the portable operation support device comprising: a position information acquirer configured to acquire a current position of the portable operation support device when in the plant, and to output current position information representing the current position; characterized in that the portable operation support device further comprises: an inspection information processor configured to add information regarding a result of an operation performed to a facility to historical data regarding operations performed to the facility, and to output the current position information regarding a position where the operation was performed to at least the facility that is associated with the historical data; an operation supporter having a plurality of functions to be performed when an abnormality is found in the facility; and a user interface configured to receive an operation by a field operator, wherein said operation supporter comprises: a function selector configured to generate a support method list based on the historical data, the support method list presenting support methods which other field operators performed to the facility in the past at the current position acquired by the position information acquirer , to generate a display image for displaying the generated support method list on a display, and to supply the generated display image to the display; said operation supporter is configured to perform processing for realizing the respective functions, for supporting field operators, in accordance with one of the support methods selected by the field operator from the generated support method list displayed on the display via the user interface . an inspection information processor configured to add information regarding a result of an operation performed to a facility to historical data regarding operations performed to the facility, and to output the current position information regarding a position where the operation was performed to at least the facility that is associated with the historical data; an operation supporter having a plurality of functions to be performed when an abnormality is found in the facility; and a user interface configured to receive an operation by a field operator, wherein said operation supporter comprises: a function selector configured to generate a support method list based on the historical data, the support method list presenting support methods which other field operators performed to the facility in the past at the current position acquired by the position information acquirer , to generate a display image for displaying the generated support method list on a display, and to supply the generated display image to the display; said operation supporter is configured to perform processing for realizing the respective functions, for supporting field operators, in accordance with one of the support methods selected by the field operator from the generated support method list displayed on the display via the user interface . a function selector configured to generate a support method list based on the historical data, the support method list presenting support methods which other field operators performed to the facility in the past at the current position acquired by the position information acquirer , to generate a display image for displaying the generated support method list on a display, and to supply the generated display image to the display; said operation supporter is configured to perform processing for realizing the respective functions, for supporting field operators, in accordance with one of the support methods selected by the field operator from the generated support method list displayed on the display via the user interface . <EOS>