The invention provides an optical modulator and an optical transmission apparatus. In the optical modulator, wire bonding is performed to narrowed and/or thickened optical modulation element electrodes while avoiding deformation of the electrodes. The optical modulator uses an optical modulation element in which an optical waveguide and a plurality of electrodes for controlling light waves propagating through the optical waveguide are formed on a substrate, in which at least one stress relieving structure is provided on an upper surface of the electrode opposite to a surface of the substrate in order to relieve stress generated due to pressure applied at the time of wire-bonding of a metal wire.