<p>Provided is an optical device wherein a gap is formed between an optical waveguide path and a substrate without disposing a depression, etc., upon the substrate, and whereon stress is not applied to an optical element even if heat is received from a heater for temperature adjustment. An optical device comprises: a substrate; an optical element further comprising an optical waveguide path which is formed on a surface which faces the substrate; a bonding part which is formed on the substrate to be located sandwiching the optical waveguide path; a heater which is formed on at least either the optical element or the substrate to heat the optical waveguide path; and a micro-bump structure which is configured from a metallic material. The bonding part and the optical element are bonded across the micro-bump structure such that a gap is formed between the optical waveguide path and the substrate.</p>
