In order to construct hemicyanine self-assembled monolayers (SAMs), we have synthesized a hemicyanine with a disulfide group. Surface plasmon resonance spectroscopy and reflection absorption spectroscopy revealed formation of the hemicyanine monolayer array on the An surface with simple immersion of the Au substrate in its ethanol solution. While many works have reported the association of H-aggregates in hemicyanine monolayers, we could not observe the H-aggregation in the present case.