A compact electronic device as a constituent element of a wireless communication system using a sensor. A first feature of the device is that a first semiconductor chip is bare-chip-mounted over a front surface of a first wiring board in the form of a chip and a second semiconductor chip is bare-chip-mounted over a second wiring board in the form of a chip. A second feature is that a wireless communication unit and a data processing unit which configure a module are separately mounted. A third feature is that the first and second wiring boards are stacked in the board thickness direction to make up the module (electronic device).