To provide an electronic unit whose productive efficiency at an assembling time is improved.

The side wall upper end of a resin casing 24 is made higher than the flange 23 of the casing 22. Positioning is made good by locating the side wall of a structure along the upper end of the resin case 24, and mating the flange 41 of the side wall and the flange 23 of the casing 22 by a mating surface S. As for a terminal 46, a position relation with side walls 44 and 45 is fixed to a structure 40 side. A mutual position relation between a plate-like terminal 46 and the side walls 44 and 45 is determined according to the mutual position relation between the side wall of the resin case 24 and a plate-like terminal 26. Accordingly, when the structure 40 is covered along the resin case 24, the suitable position of the terminal 46 is automatically set to connect to the terminal 26 by a bolt 52, and it is naturally installed at a suitable position. Therefore, the bolt 52 can be connected from a hole 50.