ELECTRICAL JUNCTION BOX

An electrical junction box 10 includes a casing 11 configured to be mounted in a vehicle, a start relay (a start electrical component) 20A housed in the casing 11 and to which a current is supplied at least at a start of the vehicle, an operational electrical component (an operational relay 20B, a connector 14, and a fuse connector 15) housed in the casing 11 and to which a current is supplied at least during an operation of the vehicle, and a surrounding heat shield wall (a heat shield wall) 24 disposed between the start relay 20A and at least one of the operational relay 20B, the connector 14, and the fuse connector 15 that are the operational electrical components. The start relay 20A includes a relay case (an electrical component case) 20a and a terminal portion 20b. The terminal portion 20b is housed in the relay case 20a and has a fixed contact FC and a movable contact MC.