1. A face detecting method, for detecting faces while varying the inclination of faces to be detected in input images, comprising: a correlative data obtaining step, for obtaining correlative data related to the inclination of faces that appear in the input images; and an order setting step, for determining the relative values of the probabilities that faces of predetermined inclinations will appear in the input images based on the correlative data, and setting the order of inclinations of faces to be detected according to an order corresponding to the relative values of the probabilities.