A method of managing a plurality of parts of an apparatus includes creating a part database of part information including at least the weights, part numbers, and shapes of individual parts, measuring the weight of a part to be ordered, entering the measured weight through input means of an information terminal and accessing the part database, extracting part information of all parts having weights which fall in a predetermined allowable range similar to the entered weight, from the part database, and displaying the extracted part information on display means of the information terminal, identifying the part number of the part to be ordered based on shapes of the parts represented by the displayed part information, and ordering the part with the identified part number.