1. A non-transitory computer-readable recording medium storing therein a search program that causes a computer to execute a process comprising: generating a Huffman tree from an XML file, leaf nodes of the Huffman tree that correspond to XML tags being different from leaf nodes of the Huffman tree that correspond to characters other than XML tags; compressing the XML file into a compressed XML file using the generated Huffman tree; receiving search input that includes a search keyword and search type of the search keyword; compressing the search keyword using the Huffman tree; setting a start flag for a compression code corresponding to an XML start tag related to the search type and an end flag for a compression code corresponding to an XML end tag related to the search type; searching the compressed XML file for the compressed retrieval keyword, between the start flag and the end flag; and decompressing searched compression code using the Huffman tree when the compressed retrieval keyword is searched.