An apparatus for processing an integrated query from various sensor networks and a method thereof are provided. The apparatus includes an integrated query parser for parsing an integrated query and analyzing a syntax of the parsed integrated query; an integrated query execution plan generator for analyzing meaning of the parsed integrated query and generating an integrated query execution query for processing an integrated query; an integrated query optimizer for optimizing a process time for the generated execution plan based on query information stored in the query information storage and sensor network information stored in the sensor network information storage; and an integrated query executer for detailing the integrated query execution plan by controlling an execution order according to the optimized integrated query and transferring the detailed integrated query execution plan to an event data process executer, a temporal data process executer, and a continuous data process executer.