To improve the usability of a face detector by selecting an optimum detection mode, according to the use in detecting facial image from an image.

A sub-window W scans on the whole image P at spaces of a plurality of pixels by a partial image forming means 11 to form a plurality of partial images PP, and the partial image PP which is a front face or a profile in a front face detecting means 30 and a profile detecting means 20 is detected out of the formed partial images PP. When switched to one of a detection rate mode, a misdetecting rate mode and a computing speed mode by a detection mode switching means, a parameter changing means 60 changes a determination score threshold Sref which determines the detecting performance of the profile detecting means 20 and front-face detecting means 30. Face detection attaching importance to detecting performance in each detection mode is performed in the profile detecting means 20 and the front face detecting means 30.