An optical signal terminating apparatus of a relay node disposed between input-side optical fibers and output-side optical fibers and acting for an optical path network, the optical signal terminating apparatus comprising: a variable filter (TFd) configured to select an optical signal of a predetermined wavelength path making up any one of a plurality of wavebands included in one wavelength division multiplexing light selected from a plurality of wavelength division multiplexing lights respectively transmitted in parallel via a plurality of optical fibers to the relay node in the optical path network, and to drop the optical signal to an electric layer, characterized in that: the optical signal terminating apparatus further comprises: an optical branching device configured to branch the plurality of wavelength division multiplexing lights from the plurality of the optical fibers (Fi1, Fi2,..., FiK); and a plurality of matrix optical switches configured to select one of the plurality of the wavelength division multiplexing lights branched from the optical branching device to output the wavelength division multiplexing light to the variable filter (TFd), and the variable filter (TFd) includes a waveband separator configured to separate the wavelength division multiplexing light into a plurality of wavebands, a waveband selector configured to select one waveband from a plurality of wavebands separated by the waveband separator, a wavelength separator configured to separate one waveband selected by the waveband selector into a plurality of wavelengths, and a drop wavelength selector configured to select and drop one wavelength from the plurality of wavelengths separated by the wavelength separator to one of a plurality of receivers included in the electric layer. the optical signal terminating apparatus further comprises: an optical branching device configured to branch the plurality of wavelength division multiplexing lights from the plurality of the optical fibers (Fi1, Fi2,..., FiK); and a plurality of matrix optical switches configured to select one of the plurality of the wavelength division multiplexing lights branched from the optical branching device to output the wavelength division multiplexing light to the variable filter (TFd), and an optical branching device configured to branch the plurality of wavelength division multiplexing lights from the plurality of the optical fibers (Fi1, Fi2,..., FiK); and a plurality of matrix optical switches configured to select one of the plurality of the wavelength division multiplexing lights branched from the optical branching device to output the wavelength division multiplexing light to the variable filter (TFd), and the variable filter (TFd) includes a waveband separator configured to separate the wavelength division multiplexing light into a plurality of wavebands, a waveband selector configured to select one waveband from a plurality of wavebands separated by the waveband separator, a wavelength separator configured to separate one waveband selected by the waveband selector into a plurality of wavelengths, and a drop wavelength selector configured to select and drop one wavelength from the plurality of wavelengths separated by the wavelength separator to one of a plurality of receivers included in the electric layer. a waveband separator configured to separate the wavelength division multiplexing light into a plurality of wavebands, a waveband selector configured to select one waveband from a plurality of wavebands separated by the waveband separator, a wavelength separator configured to separate one waveband selected by the waveband selector into a plurality of wavelengths, and a drop wavelength selector configured to select and drop one wavelength from the plurality of wavelengths separated by the wavelength separator to one of a plurality of receivers included in the electric layer.