A portable terminal for managing a printer, comprising: an input device that inputs maintenance information indicating a state of the printer from the printer; a display; and a controller that analyzes the inputted maintenance information, converts the inputted maintenance information into a format suitable for display of the display, based on this analysis result, and controls the display, so as to display the converted maintenance information as the management information of the printer on the display; wherein the input device includes a communication device to receive the maintenance information to be transmitted from the printer by wireless communication, characterized in that said portable terminal further comprises: a storage device to store reference data indicating a specification range of the printer for each of the plurality of data of the maintenance information, which is a value set for each of the plurality of data of the maintenance information as a range in which the printer can normally operate, and in that : the controller compares each of the plurality of data of the maintenance information with the reference data stored in the storage device; and the display displays whether or not each of the plurality of data of the maintenance information is within the specification range, as this comparison result. an input device that inputs maintenance information indicating a state of the printer from the printer; a display; and a controller that analyzes the inputted maintenance information, converts the inputted maintenance information into a format suitable for display of the display, based on this analysis result, and controls the display, so as to display the converted maintenance information as the management information of the printer on the display; wherein the input device includes a communication device to receive the maintenance information to be transmitted from the printer by wireless communication, characterized in that said portable terminal further comprises: a storage device to store reference data indicating a specification range of the printer for each of the plurality of data of the maintenance information, which is a value set for each of the plurality of data of the maintenance information as a range in which the printer can normally operate, and in that : the controller compares each of the plurality of data of the maintenance information with the reference data stored in the storage device; and the display displays whether or not each of the plurality of data of the maintenance information is within the specification range, as this comparison result. a storage device to store reference data indicating a specification range of the printer for each of the plurality of data of the maintenance information, which is a value set for each of the plurality of data of the maintenance information as a range in which the printer can normally operate, and in that : the controller compares each of the plurality of data of the maintenance information with the reference data stored in the storage device; and the display displays whether or not each of the plurality of data of the maintenance information is within the specification range, as this comparison result. the controller compares each of the plurality of data of the maintenance information with the reference data stored in the storage device; and the display displays whether or not each of the plurality of data of the maintenance information is within the specification range, as this comparison result. <EOS>