An operation support system for supporting an operation to each facility installed in a plant, the operation support system may include, but is not limited to, a data storage that stores historical data which represent information regarding operations performed to the facility as history, and at least one operation support device portable by a field operator, wherein the operation support device may include a position information acquirer configured to acquire a current position of the operation support device, and to output current position information, an inspection information processor configured to add information regarding the operation performed to the facility, and to output the current position information regarding position where the operation was performed to at least the facility that is associated with the historical data to data storage, and an operation supporter configured to represent information regarding the operation performed to the facility as operation information based on the historica
