A casing body of a junction box is made of a resin molded product. A vehicle body bracket engaging portion projects from an outer surface of the casing body. The engaging portion is engaged with a vehicle body bracket made of a metal material or other relatively high-strength that projects from a vehicle body. A coupling portion integrates the vehicle body bracket engaging portion with a second engaging portion that is shaped to engage with a separate member, such as a cover that attached to the casing body, thereby reinforcing the vehicle body bracket engaging portion.