An optical modulator component 2 has a substrate 4 for modulation made of an electro-optical material and having a joining face 4b; an optical waveguide 6 provided in or on the substrate 4 and having at least one pair of branched portions 6c; and a radio-frequency interaction portion 11 applying a voltage on the respective branched portions 6c to modulate light propagating through the branched portions. The optical waveguide 6 has end faces 15A, 15B, 15C and 15D present on the joining face 4b of the substrate 4 for modulation.