An electronic controller for a vehicle includes a box-shaped frame having only one opened side that has a notch portion into which an electric connector whose connection port protrudes toward an outside fits and a cover that closes an opening of the frame, in which while a groove filled with a sealant is provided at least on a bonded surface of an electric connector to which the cover is bonded, a first convex portion that fits into the groove is provided in a circumferential portion of the cover. Moreover, the electric connector has a flange portion opposite to an inner wall of the frame around the notch portion, and the flange portion is provided with a second convex portion protruding toward the inner wall to surround the notch portion.