An information terminal apparatus includes: a function execution section that executes an acquisition function which acquires a sound or an image that is of a same kind as an acquisition function which acquires a sound or an image that an external device includes, as a substitutional function instead of the external device; a display section; a communication section that performs communication with one or more external devices that co-operate with the information terminal apparatus; and a control section that, in a co-operation mode, before co-operating with the external device and causing execution of the acquisition function which acquires a sound or an image that the external device includes through the communication section, executes a co-operation preparation mode that includes causing the substitutional function of the function execution section to be executed and display control for performing settings relating to the acquisition function which acquires a sound or an image.