The present invention is to provide an optical transceiver that installs a bi-directional optical sub-assembly. The bi-directional sub-assembly is installed within the transceiver and fixed by the holder with a pair of legs put the sub-assembly therebetween. By press-fitting these legs into respective pockets provided in the side of the transceiver, the sub-assembly is to be fixed with the housing. To press-fit the holder completes the fixing and the positioning of the sub-assembly at the same time.