To display an advertisement on the basis of only an input image.

A feature quantity acquiring part 36 acquires a feature quantity of an input image input to a server 11. A keyword obtaining part 37 obtains a keyword of the input image based on the feature quantity of the input image. A related image acquiring part 38 acquires a related image on the basis of the keyword of the input image. The feature quantity acquiring part 36 acquires a feature quantity of the related image. The keyword obtaining part 37 obtains a keyword of the related image on the basis of the feature quantity of the related image. An advertisement acquiring part 39 acquires an advertisement on the basis of the keyword of the input image and the keyword of the related image. The input image, the keyword of the input image, the related image, the keyword of the related image and the advertisement are read out by a communication I/F 35 and output from the server 11.