A multifunctional apparatus is capable of switching between a standard operation mode in which a Web service layer stops operating and an OS mode in which the Web service layer operates. In the OS mode, the multifunctional apparatus informs an external control apparatus of pressed-hardware-button information indicative of a pressed hardware button detected by a user interface layer. In the control apparatus, an event process section reads out, from a shortcut button storage section, process-contents information corresponded with button identification information indicative of the hardware button indicated by the pressed-hardware-button information, and a device control section transmits, to the multifunctional apparatus, a control instruction for executing a device process indicated by the process-contents information. Thereafter, in the multifunctional apparatus, the Web service layer acquires the control instruction from the control apparatus and executes the device process in accordance with the acquired control instruction. This allows for realizing a system for controlling a multifunctional apparatus, capable of executing, with only one touch, a process that has been registered.