The utility model relates to an electric junction box. A first box body is provided with a plurality of first side walls which are arranged by extending in the first direction in the inner space which is surrounded. Two layers walls divisions are arranged on the side wall which is arranged on the upper side at least inside a plurality of first side walls of the first box body. Through arranging a first wall division and a second wall division, A groove is formed between the side wall which is at least arranged on the upper side and the second wall division. The first wall division is arranged by extending from the side wall which is arranged at least on the upper side in the second direction which is approximately vertical to the first direction. The second wall division is arranged by extending from the first wall division continuously in the first direction. The second box body is provided with a plurality of second side walls which are arranged by extending on the first direction. Through tabling a plurality of second side walls on the outer sides of a plurality of first side walls, the inner space is sealed. A rib is arranged by extending from the front end of the side wall which is embedded in the groove inside the second side wall continuously in the second direction.