An appropriate search is carried out even with images including a complicated layout structure, decorated characters, and so on. An image search device 10 is provided with an image database 11 to store an image as a search target, a character string region extraction unit 13 to extract a character string region including a character string in the image, a character candidate recognition unit 14 to specify a plurality of character candidates through execution of character recognition from the image, for each of characters forming the character string in the character string region, a character candidate storage unit 15 to store the plurality of character candidates in the sequence of the character string in correspondence with the image as the specifying origin of the character candidates, a search keyword input unit 17 to input a search keyword, a search unit 18 to perform a search to determine whether each of characters forming the search keyword matches any of the plurality of character candidates for the character string, and an output unit 19 to output the result of the search.