1. A relay apparatus comprising: an associative memory for searching for an address of data relating to a data word; a contents memory for storing data corresponding to the address searched for by the associative memory; a chip for searching the contents memory for data relating to the data word when the data word is designated and outputting the data, the chip storing a conversion table for converting an address of the contents memory to an associative memory address on the associative memory; a conversion unit for converting an associative memory address corresponding to a data word to an address of the contends memory when the data word is designated and the associative memory address is searched for by the associative memory; and an output control unit for searching for an associative memory address corresponding to the data word based on the address of the contents memory and the conversion table and outputting the associative memory address as the search result.