To provide a battery remaining quantity warning device which makes it possible to efficiently and sufficiently use the electricity of a battery and enables a user to select a mode according to the remaining quantity.

An A/D converter 12 constantly measures the voltage value of the battery 4. When the voltage value of the battery 4 falls to a prescribed level as the battery 4 is consumed and so on, an A/D converter 10 applies a pulse signal to a simulated load circuit 6, the voltage across the battery 4 when the pulse signal is applied is measured and the A/D converter 12 detects a voltage drop across the battery 4. When the voltage drop across the battery 4 is detected, warnings of source voltage drop corresponding to modes, such as the recording mode, reproduction mode, and electronic flash charging photographic mode of a digital camera, are simultaneously displayed on an LCD 28 for data.