An electrical junction box for a vehicle has a connector module for connection in use to electrical connectors, a fuse module carrying fuses, and a relay module connected to relays. The connector module includes circuit plates stacked one on another to form a layered assembly which is mounted vertically. The fuse module has a circuit plate and is mounted at a lower opening of a casing so that it is accessible for insertion and removal of fuses. The circuit plate of the fuse module is perpendicular to the main faces of the layered assembly. A compact construction permitting easy access to the fuses is obtained.