In conventional image authentication apparatuses, in a case in which relatively significant variation of a face image is accompanied when a part of a face is hidden by a mask or sun-glasses, etc. during a matching operation, it has been difficult to treat the image as an authentication target. When the part of the face is also hidden by the mask or the sun-glasses, etc. during the matching operation, by outputting a recollected image, using as an input image a face image extracted by a target extraction unit, by an image recollection unit provided with an associative memory circuit, partial hiding and facial-expression variation, etc. included in the input image are complemented; thereby, application range is expanded so that face authentication can also be performed in a face image including relatively significant variation.