Disclosed is an information providing system using a network. The information providing system comprises a tag for transmitting a tag identification code, a mobile communication terminal for receiving the tag identification code through a first network, generating map request data and transmitting the map request data together with the tag identification code, a first computer for transmitting the tag identification code and the map request data, which are received from the mobile communication terminal through a third network, through a second network, a third computer for providing map data through the second network, and a second computer for receiving the tag identification code and the map request data through the second network, receiving the map data from the third computer, and transmitting the map data to the first computer. The first computer transmits the map data to the mobile communication terminal through the third network.