1. An image forming apparatus operated by a mobile terminal, comprising: a function performance information storage section which stores function performance information representing performance of a function provided in the image forming apparatus; a function performance information receiving section which receives the function performance information representing performance of a function provided in the mobile terminal from the mobile terminal; and a function selection section which compares the function performance information of the image forming apparatus with the function performance information of the mobile terminal to select the function for which the performance of the image forming apparatus is determined to be superior, wherein the image forming apparatus transmits the information representing the function which is not selected by the function selection section to the mobile terminal, and performs the processing of the function selected by the function selection section.