An optical control device includes a photonic crystal and a line-defect waveguide formed in the photonic crystal wherein the optical control device is capable of guiding, through the line-defect waveguide, a light having a wavenumber larger than a wavenumber corresponding to an anti-intersection of an even-mode band and an odd-mode band, the even-mode band and odd-mode band being a waveguide band of the line-defect waveguide, wherein the even-mode band of the line-defect waveguide includes two or more inflection points in a wavenumber region larger than a wavenumber corresponding to an intersection of the even-mode band and said odd-mode band, the optical control device guiding a light having a frequency in the vicinity of the inflection point.