To improve a stability of processing operation by adaptively adjusting the timing at which the processing operation is stopped.

A mode processing apparatus includes an MCU 14. The MCU executes a processing operation according to one of an audio reproducing mode and an audio recording mode, by using a battery 42 as a power supply. The MCU 14 cyclically determines, in parallel with the processing operation according to an operating mode at a current time point, whether a terminal voltage Vbat of the battery 42 is equal to or less than a threshold value. When a determination result indicating (the terminal voltage Vbat)(the threshold value) is continued, the MCU requests to stop the processing operation according to the operating mode at a current time point. Moreover, the MCU 14 adjusts a length of a cycle in which the above-described determining process is performed to a length different depending on each operating mode.