Provided is a mobile terminal device that can prevent print data from being erased due to a battery exhaustion. This mobile terminal device have a battery as a power source, constructs print data (PD) from print target data stored in a volatile storage part to transmit to an image forming apparatus (IFA), and causes the IFA to execute printing of the PD. The mobile terminal device includes a non-volatile storage part, a battery residual amount detection part configured to detect a residual amount of the battery, and a print allowance/disallowance determination part configured to store, pursuant to a determination thereof, the PD in the non-volatile storage prior to a transmission of the print data based on the residual amount of the battery detected by the battery residual amount detection part, that no power required for transmitting the PD is ensured.