An electric junction box includes a current detection device. The current detection device has a magneto-electric conversion element and a magnetic core having a disposing space in which this magneto-electric conversion element is disposed, to detect magnetic flux occurring on the magnetic core as a current. The magnetic core has a bus bar insertion space through which a bus bar from which the current is to be detected is inserted, which bus bar has an insertion portion which is formed not to be larger than a width size of the disposing space in the magnetic core and to be inserted into the disposing space.