Optical transceiver module

PROBLEM TO BE SOLVED: To provide a transceiver module capable of easily and quickly being mountable and demountable, and capable of easily and speedily being manufactured at a low cost, and to provide a receptacle assembly for receiving the module. SOLUTION: This transceiver module 10 has a main housing 12 comprising a surrounding body 64 with a sorrounding member 62 inserted. A circuit board 60 is sorrounded by the member 62. An optical sub-assembly is provided on the circuit board 60. The optical sub-assembly passes through a recess to be extended to an outside of the surrounding body 64. A recess cover is provided to form sealing for preventing a liquid from leaking between the sorrounding body 64 and the optical assembly. A module housing is plug-connectable via a release lever having a detent received into a hole of the receptacle and a plug connecting connector of the module 10 connected to an inside of the receptacle. The receptacle contains an earthing means such as an earthing clip provided in its inside, and a protection door for restricting electron emmision.