1. A face meta-data generating apparatus comprising: a face feature extracting unit which extracts a face feature from a face image; and a confidence index extracting unit which extracts a confidence index indicative of a confidence to said face feature, from said face image, wherein said face feature and said confidence index are generated as a face meta-data, said confidence index extracting unit comprises: a first confidence index extracting unit which extracts a contrast index of said face image; and a second confidence index extracting unit which extracts as an asymmetric index of said face image one of a maximum value of differences between said face image and a flipped image obtained by flipping said face image, and one of a sum and an average of powers of pixel values of difference images between said face image and said flipped image.