A change in a subject is quickly sensed and a focusing lens is driven with degradation in durability and out-of-focus states of output video images due to driving of the focusing lens more than necessary avoided. To achieve the object described above, the invention relates to an imaging apparatus that controls a focusing lens based on a contrast signal provided from a video signal and includes a controller that performs first evaluation based on comparison between the value of the contrast signal and the value of a main threshold, performs second evaluation after the first evaluation based on comparison between the value of the contrast signal and a sub-threshold that is greater or smaller than the main threshold and is set to decrease or increase with the lapse of time, and performs focus control on the focusing lens based on a result of the second evaluation.