A digital camera includes an image pickup device which converts incident light of an object image into an electrical signal during an exposure operation; a processor which captures the electrical signal, and thereafter generates a digital image from the electrical signal; a battery checking device which performs a battery check process for determining whether a battery voltage of the digital camera is lower than a predetermined voltage level; a controller which forcibly terminates the exposure operation when the battery checking device determines that the battery voltage drops below the predetermined voltage level during the exposure operation, and subsequently makes the processor start capturing the electrical signal in order to generate a backup digital image; and a warning device which warns a user that the exposure operation is forcibly terminated due to a shortage of the battery voltage and that the backup digital image is underexposed, in the case where the exposure is forcibly terminated.