This invention enables an operation checker to easily select a specific one of a plurality of servers on a load distribution system and cause the selected server to respond to a request for a server test or operation monitoring. To accomplish this, a Web service system (1) includes Web servers (10, 20, 30) in which service applications to respond to a request transmitted from a client (2) are installed, and a general-purpose load distribution apparatus (40) which transfers the request from the client (2). Each of the Web servers (10, 20, 30) acquires, from the request received from the client (2), server designation information to designate a Web server that should respond to the request from the client (2). The Web server transmits, to the client (2), cookie information of the client (2) together with the server designation information.