An application switch system includes a switch configured to control a connection between a plurality of client terminals and a plurality of servers which exist on a network, a relay unit configured to perform a protocol relay, and a controller that includes a section configured to perform a centralized control on a route table used to determine a destination in the switch, a section configured to control relay processing of the relay unit, a section configured to select one server as a connection destination from the plurality of servers, a section configured to select a route which links between one client terminal of the plurality of client terminals and the selected connection destination server, and which contains the relay unit, and set the selected route to the route table in the switch, and a section configured to set relay information used when the relay unit performs the protocol relay.