1. An apparatus for photographing a subject using a digital camera having a display window, comprising: an image sensor for capturing a predetermined plurality of images of a subject, including images of a face of the subject, for a predetermined time period; a first image signal processor for processing the predetermined plurality of images in order to display at least one of the predetermined plurality of images as a preview image on the display window, wherein the first image signal processor includes: an image selecting unit for selecting the predetermined plurality of images including respective face areas therein for a predetermined time period; an image detecting unit for detecting every face area selected in the image selecting unit; and an image tracking unit for tracking a motion of every face area detected in the image detecting unit in order to search for an identical face; a buffer for storing the preview image including the corresponding detected face area; a capture button for capturing a still image during outputting of the preview image on the display window; a second image signal processor for processing the captured still image in response to the capture button; a controller for controlling to store the captured still image and information related to the detected face area detected from the first image signal processor prior to the activation of the capture button; and a memory for storing the processed still image together with the information related on the detected face areas.