An electric junction box having an aperture on one side of a case that houses conductive material, the aperture receiving a subsequently installed component when the electric junction box is assembled. The conductive material mounted in the case is exposed at the aperture; wires connecting to other conductive material are passed through the aperture; and a cover provided inside the aperture is folded to cover the conductive material while the wires are installed, preventing interference of the wires with the subsequently installed part.