A hermetically sealing member with an optical transmission means transmits an optical signal economically and practically between the inside and the outside of a shielding member covering a printed-circuit board while sustaining the hermetically sealed state certainly. An optoelectronic device and an optical transmission method are also provided. A hermetically sealing member with an optical transmission means includes a gasket body fixed between a printed-circuit board and a sealing face of a shielding member, and a tape fiber formed integrally with the gasket body.