A connection adapter includes: an adapter housing； a split sleeve； and a spacer having a space determiner disposed inside the split sleeve and an angle determiner that passes through the slit of the split sleeve to be secured relative to the adapter housing. The two connector connection pars are each connected to the connectors, respectively, causing the ferrules of the connectors to be fitted into the split sleeve and secured across the spacer, so that the single mode optical fibers of the connectors are optically connected to each other via no point of contact therebetween, to thereby provide a connection adapter capable of creating stable connection efficiency for optical fibers and an endoscope device using the connection adapter.
