A circuit board (32) has a board main body (32M), a pair of first electrodes (32d) for contact with and electrical connection to electrodes (91c) of a liquid consuming apparatus, the first electrodes (32d) being formed on a first surface of the board main body (32M), and a pair of second electrodes (32e) for contact with and electrical connection to terminal plates (45) of a sensor unit (35), the second electrodes (32e) being formed on an opposite, second surface of the board main body (32M) and electrically connected respectively to the first electrodes (32d).