When information is transmitted among a plurality of devices connected through a network, an information opening data storage section for opening predetermined information is set to devices connected through the network, the information opening data storage section is formed in a descriptor format having a predetermined hierarchical structure, predetermined information is stored in a board 910 set in the descriptor format, the position at which the predetermined board 900 is stored is directly instructed by the highest-order descriptor 900 having the hierarchical structure, and information concerning a predetermined information is stored in information areas 921, 922, 931, 932 instructed when the hierarchical structure is retrieved from the highest-order descriptor 900.