The router which relays a transfer request and a reply between master and slave components has request-control circuits provided therein. The request-control circuits judge the slave component to transfer a request from each master component to, and arbitrate the conflict between requests to one slave component. Further, for the router, a slave-component-allocation-control circuit which variably allocates the slave components to be connected to the request-control circuits to the request-control circuits is adopted. In case that a slave component in connection with one request-control circuit is subjected to no access, changing the allocation of the slave component in connection with the one request-control circuit makes possible to utilize the resource of the one request-control circuit.