In order to stably detect a flicker under an illumination of a fluorescent lamp with an XY-addressed-scanning type image sensor used and to cancel the flicker, the present invention provides an image sensing device, wherein a video signal in any area on an imaging plane is first integrated per frame period, then an integrated value in a current frame is sequentially compared with a one-frame previously integrated value, next whether a variation pattern of the integrated value matches one of flicker patterns when the flicker occurs is determined, then an existence of the flicker is determined when an identical flicker pattern is seen more than two consecutive times.