In a method of manufacturing an optical device, a whole substrate is first prepared which has a plurality of regions corresponding to substrates constituting a plurality of optical devices, respectively. A plurality of chips are then mounted to the plurality of regions, respectively. A whole sealing member having a plurality of sealing members is integrally attached to the whole substrate to form an intermediate body. The intermediate body is divided into the above-described regions. Thus, the optical device having a substrate, a chip as an optical element mounted to the substrate and a sealing member with transparency provided at the substrate for the purpose of sealing the chip is manufactured. This manufacturing method improves the efficiency of manufacturing an optical device.