Plural contacts include other ends on which first substrate connections that are connected to the signal electrodes of a substrate are formed. A shell includes an upper plate that covers the whole of the plural contacts on the substrate. Side plates block both ends of the first substrate connections in an array direction (x-axis direction) between the upper plate and the substrate and include edges which face the substrate and on which second substrate connections connected to the ground electrode of the substrate are formed. A back plate blocks the fronts of the first substrate connections with respect to contactors between the upper plate and the substrate and includes an edge which faces the substrate and on which third substrate connections connected to the ground electrode of the substrate are formed.