1. A key word detection device for detecting a search key word from a target image in order to perform a search with a search engine on the internet, the key word detection device comprising: a processor configured to operate as a feature point detector configured to detect a feature point of a specific character string from the target image, the specific character string prompting a user to perform the search; a key word recognition unit configured to recognize a character string existing in surroundings of the feature point detected by the feature point detector as the search key word in the target image; and a storage for storing character information and data of the target image used by the processor.