An alarm unit includes an apparatus and a method of maximizing the efficiency of an alarm function that wakes up a sleeping user. An image input unit capable of photographing an eye image as a criterion for determining if the user has woken up is mounted on an alarm control apparatus. The image input unit mounted alarm control apparatus photographs a face image of the user, detects the eye region from the face image, and then determines a state of whether the user has woken up or not based on movement of the pupils in the eye region. If it is determined that the user keeps a waking state for a certain time, an alarm function is cancelled. By doing this, the alarm unit can help prevent the user from easily cancelling an alarm and maximize the efficiency of an alarm function that wakes up a sleeping user.