1. A method of recognizing a user's dynamic organ for use in an electric-using apparatus, the method comprising: comparing a background image and a target image, which are inputted through an imaging element, to detect a candidate region including portions of the target image that are different between the background image and the target image; scanning the candidate region using a window; generating a histograms of oriented gradients (HOG) descriptor of a region of the target image that is scanned when it is judged that the scanned region includes a dynamic organ; measuring a resemblance value between the HOG descriptor of the scanned region and a HOG descriptor of a query template for a gesture of the dynamic organ; and determining that the scanned region includes the gesture of the dynamic organ when the resemblance value meets a predetermined condition.