An imaging apparatus includes a usable time calculation unit which calculates a usable time of a battery device having a secondary battery, wherein the usable time calculation unit measures an average power level while a component is performed at a predetermined operation mode, wherein the power consumption of the component is unknown in advance before the component is initially connected, and when power is supplied for the second and subsequent times while the component is continuously connected, the usable time calculation unit calculates the usable time of the battery device using the average power level and a current integration value which is an integration value of current flowing during charging and discharging of the battery device.