A conductor connecting structure includes: first and second conductors having terminal portions; a support having recessed portions; first screw members accommodated in the recessed portions; and second screw members that co-fasten the terminal portions of the first and the second conductors by screwing to the first screw members. The recessed portions have first and second wall surfaces that face each other in an opposing direction, and restricting surfaces along the opposing direction to restrict the rotation of the first screw members. The first and second wall surfaces configure a retaining portion to retain the first screw member before being screwed, and an allowable portion located closer to the inlet of the recessed portion. The distance between the first and the second wall surfaces in the allowable portion is greater than the distance in the retaining portion.