To simplify a mold for forming drain holes in a junction box with reinforcements.

Reinforcements 4a are made to protrude at least from a bottom wall 3 of a junction box main part 1 of an electrical junction box and drain holes 6 are formed in the reinforcements 4a. The reinforcements 4a are formed, so as to protrude toward the inside of the junction box main part 1 and the drain holes 6 are formed in side walls 5 of the reinforcements. The drain holes 6 are formed across the bottom wall and lower surfaces 7a of upper side walls 7 of the reinforcements 4a. The drain holes 6 are formed at crossing parts of side walls 2 and the bottom wall 3 of the junction box main part 1. Reinforcements 4b are extended along the side walls 2 and the drain holes 6 are formed at crossing parts of the side wall side reinforcements 4b and the bottom wall side reinforcements 4a. The side walls 2 and the side wall side reinforcements 4b are inclined. The drain holes 6 are formed on extensions of crossing parts of the side walls 2 and an inclined wall 10 adjacent to the side walls 2.