An information processing device (central apparatus (2)) in a sensor network system is arranged so as to include an input-output processing section (101); an information converting section (103) and a resource specification information recognizing section (104) for dividing target information which is requested with the information request signal into a combination of information elements which appropriately compose the target information; a data acquiring section (107) for acquiring data of sensing results; and an input-output processing section (101) for outputting information based on the data acquired by said data acquiring section.