1. A biometrics authentication device comprising: a non-directional feature generation process unit configured to extract, from an input image, directional features corresponding to directions different from each other and to generate a non-directional feature on the basis of the directional features; a directional feature generation process unit configured to extract, from the input image, directional features corresponding to directions different from each other and to select, from among the directional features, a reference directional feature corresponding to a reference direction; a non-directional feature matching process unit configured to obtain a first degree of similarity between the non-directional feature and a registered non-directional feature stored in a storage unit; a directional feature matching process unit configured to obtain a second degree of similarity between the reference directional feature and a registered reference directional feature stored in the storage unit; and a determination unit configured to make a weight of the second degree of similarity smaller than a weight of the first degree of similarity and to determine whether or not a subject is a person to be authenticated, by using the first degree of similarity and the second degree of similarity.