A low-loss rectangular-passband multiplexer including a three-arm interferometer coherently connected to a waveguide grating router, resulting in a passband substantially of type N=3, without intrinsic loss. A subscription level associated with a connection is determined. The plurality of columnar spacers formed on the second substrate are not arranged at even intervals in the longitudinal direction of the scan line, andor are not aligned on the line but are arranged at random. In an applying process, at least one target string is selected from among all the strings in a user’s input sentence through the dictionary. The valve element includes a forward pressure receiving face on which fluid in the flow path acts in a valve-opening direction in a closed state of a valve and a reverse pressure receiving face on which the fluid acts in the valve-closing direction in the closed state of the valve and both the pressure receiving faces have substantially equal pressure receiving areas.