Circuit modules including identification codes and a method of managing them are provided. A module substrate includes signal input output terminals and outer ground terminals provided at the peripheral portions of a surface which becomes a mounting surface when the circuit module is completed. An inner-ground-terminal formation area surrounded by the signal input output terminals and the outer ground terminals includes a plurality of inner ground terminals arranged in a matrix of rows and columns. One of the edge portions is a direction identification area. The inner ground terminal is not provided in the direction identification area, and a first identification code having information about the position of the module substrate is provided in the direction identification area.