The present invention provides an optical adapter, which can suppress electromagnetic waves from an optical communication module, is provided. An optical adapter comprises: a housing; an optical fiber which is housed in the housing; and a ferrule which is housed in the housing. The housing has a first edge to be inserted into a receptacle of an optical communication module, and a second edge for insertion of an optical connector plug. The optical fiber has a first edge to optically couple with the receptacle, and a second edge to optically couple with the optical connector plug. The ferrule houses the optical fiber. At least a part of the housing or at least part of the ferrule is formed of an electromagnetic absorption material.