The present invention is to provide an intelligent pluggable transceiver improving an EMI tolerance with a simple mechanism. The optical transceiver of the invention comprises upper and lower housings (11, 12), a holder (81), optical assemblies (51, 61), a cover (14), a substrate (15) and a grip (13). The optical assemblies are fixed with the upper and lower housings together with the holder with interposing the conductive elastic member. Although the rear end of the substrate exposes outside the transceiver, the shield gasket and the ground pattern on the substrate shields the contact portion between the substrate and the upper housing and between the substrate and the cover. Moreover, the grip and the latch lever installed in the lower housing, and the elastic piece realize the latching/releasing mechanism of the transceiver with the host system.