A junction box includes a box body, an upper cover, and a side cover. The box body has a side wall portion, an electric distribution portion, and a drain hole which is located at the inside of the side wall portion. The upper cover has a top panel and a down wall portion which are downwardly provided from the peripheral end of the top panel. The side cover has a terminal connected to the electric distribution portion and a case portion which covers the terminal. A drain groove is provided on an upper face of the case portion along the side wall portion. A downward slope is formed towards the drain hole on a bottom face of the drain groove.