To make efficiently transmittable multimedia data to plural client terminals in server machine, which has plural communication boards and transmits multimedia data to plural client terminals.

A load condition management part 11a manages load conditions of communication boards 17-1 to 17-n. When a transmission request of multimedia data to a client terminal 30-i is outputted from an application program 11, a communication board selective control part 13 selects the least loaded communication board 17-j out of communication boards 17-1 to 17-n, and a connection/disconnection control part 14 uses this selected communication board 17-j to set a communication path with the client terminal 30-i, and a data transmission/reception control part 15 uses this communication path to transmit multimedia data to the client terminal 30-i.