An image forming apparatus comprising means for communicating with a mobile terminal, characterized by comprising: an operation panel configured to display an operation screen and to receive an input operation by a user; an operation panel processing section which performs processing of the user input operation; a function performance information calculation section (110a, 110b, 110c) which, for each of a display function, a image data processing function, and a communication function, respectively, that are executable by the image forming apparatus, converts an individual performance value indicating performance of each of elements of hardware or software used at the time of realizing the function into a point based on a predetermined weighting to the individual performance value and, calculates a total of all the converted points for the elements as function performance information representing performance of the respective functions; a function performance information storage section (120a, 120b, 120c) which stores the function performance information of each of the display function, the data processing function, and the communication function that are calculated by the function performance information calculation section (110a, 110b, 110c); a function performance information receiving section which, for each of a display function, an image data processing function, and a communication function, that are respectively executable by the mobile terminal, receives a total of points into which respective individual performance values indicating performance of elements of hardware or software used at the time of realizing the function are converted as function performance information representing performance of the function from the mobile terminal; a function selection section which, when operation of the image forming apparatus is started, for each of the display function, the image data processing function, and the communication function, compares the function performance information of the image forming apparatus with the function performance information of the mobile terminal, selects a device having superior performance among the image forming apparatus and the mobile terminal, and transmits, to the mobile terminal, device selection information indicating which of the image forming apparatus and the mobile terminal has been selected and a control section that, after the device having the superior performance for each of the display function, the data processing function, and the communication function has been selected by the function selection section, performs processing of the function in which the image forming apparatus is selected by the function selection section. an operation panel configured to display an operation screen and to receive an input operation by a user; an operation panel processing section which performs processing of the user input operation; a function performance information calculation section (110a, 110b, 110c) which, for each of a display function, a image data processing function, and a communication function, respectively, that are executable by the image forming apparatus, converts an individual performance value indicating performance of each of elements of hardware or software used at the time of realizing the function into a point based on a predetermined weighting to the individual performance value and, calculates a total of all the converted points for the elements as function performance information representing performance of the respective functions; a function performance information storage section (120a, 120b, 120c) which stores the function performance information of each of the display function, the data processing function, and the communication function that are calculated by the function performance information calculation section (110a, 110b, 110c); a function performance information receiving section which, for each of a display function, an image data processing function, and a communication function, that are respectively executable by the mobile terminal, receives a total of points into which respective individual performance values indicating performance of elements of hardware or software used at the time of realizing the function are converted as function performance information representing performance of the function from the mobile terminal; a function selection section which, when operation of the image forming apparatus is started, for each of the display function, the image data processing function, and the communication function, compares the function performance information of the image forming apparatus with the function performance information of the mobile terminal, selects a device having superior performance among the image forming apparatus and the mobile terminal, and transmits, to the mobile terminal, device selection information indicating which of the image forming apparatus and the mobile terminal has been selected and a control section that, after the device having the superior performance for each of the display function, the data processing function, and the communication function has been selected by the function selection section, performs processing of the function in which the image forming apparatus is selected by the function selection section.