Provided is an electrical junction box having a novel structure, said electrical junction box having a connector exposed to the outside of a case through an opening of the case, and being capable of preventing foreign material from entering through a gap between the opening and the connector. A protruding plate section (28) is formed to a connector (22) housed in an opening (36) of a case (18), said protruding plate section extending parallel to a circuit board (20), a cover plate section (42) for covering the protruding plate section (28) is formed on the inner circumferential surface (40a) of the opening (36) of the case (18), said cover plate section being positioned on the opposite side to the circuit board (20) with respect to the protruding plate section (28), and the gap between the connector (22) and the opening (36) of the case (18) is closed by means of the protruding plate section (28) and the cover plate section (42).