A circuit board module is electrically connectable to a socket by inserting one end part thereof into the socket, and includes a circuit board and a terminal board having a first surface provided with a column of socket-connection pads and mounted on the surface of the circuit board at the one end part. The terminal board includes first, second, and third pad columns provided on a second surface of the terminal board opposite to the first surface. The circuit board includes fourth, fifth, and sixth pad columns respectively provided on the surface of the circuit board opposing the second surface of the terminal board, at positions opposing the first, second, and third pad columns of the terminal board, respectively.