An optical device includes: a light transmissive first substrate; a light transmissive second substrate; a polarizing layer disposed between the first substrate and the second substrate; a first bonding layer which bonds the first substrate to the polarizing layer; and a second bonding layer which bonds the second substrate to the polarizing layer, wherein the first bonding layer is an adhesive layer, and the second bonding layer contains a structure of siloxane (Si—O) and a leaving group. By forming the first bonding layer of an adhesive layer, a necessary strength can be ensured, and also the optical properties can be enhanced by absorbing the irregularities of the polarizing layer formed of a synthetic resin so as to prevent the contamination with air bubbles. Since the time of exposure of the polarizing layer to heat generated by a plasma can be decreased, the polarizing layer is not deteriorated.