To provide an imaging device capable of performing photographing without other people being conscious of stroboscope light for photographing that requires a slow shutter speed.

A digital camera 100 compares luminance values of video signals of frames acquired during non-light emission and light emission of a stroboscope 48 with each other to determine presence or absence of reflection light from a subject to stroboscope light emission. When it is determined that the reflection light exists, photographing is performed by implementing division light exposure. On the other hand, when it is determined that no reflection light exists, photographing is performed by implementing long second exposure.