1. A system for supporting a logical sensor network (LSN), comprising: a computer having a memory, comprising a metadata database (DB) for storing metadata of a plurality of available physical sensor networks (PSNs) each having a plurality of sensor nodes; a LSN generation module for generating a LSN including one or more PSNs among the PSNs stored in the metadata DB or one or more sensor nodes in the PSNs, and storing metadata of the generated LSN in the metadata DB; a LSN update module for updating the metadata of the LSN including the PSNs or the sensor nodes in the PSNs when a state of the PSNs or the sensor nodes is changed; and a query processing module for, when a query about the LSN is received from an application program, collecting sensing data from the updated PSNs or the sensor nodes included in the LSN, generating query result data for the LSN using the collected data, and providing the query result data to the application program, wherein the LSN generation module determines whether or not a LSN is generated by examining whether the selected PSNs or sensor nodes support a sensing type in common; wherein the LSN generation module generates the LSN using the selected PSNs or sensor nodes when the selected PSNs or sensor nodes support a sensing type in common, and stores metadata of the generated LSN in the metadata DB.