Disclosed is an auto-focus apparatus including an evaluation value calculator periodically calculating evaluation values using high frequency components of image signals in a specific region of a subject image. The auto-focus apparatus further includes a control unit for outputting instruction values provided to a lens driver based on the evaluation values, conducting operation to search the peak of the evaluation values while moving positions of the focus lens, returning the lens to the position corresponding to the point at which the relative maximum has been detected after having detected the relative maximum of the evaluation values, obtaining the evaluation values calculated by the evaluation value calculator, and determining whether or not the evaluation value satisfies a prescribed condition; and a storage for storing determination results. In the auto-focus apparatus, the control unit determines whether or not the auto-focus apparatus includes abnormal portions based on the determination results.