A case for an electronic device has a hollow body which forms at least one receiving housing for an electronic device (E) and has an access opening to the housing surrounded by a peripheral edge outside the housing which has a truncated conical or truncated pyramidal shape converging on the opening. The case further includes a cover for closing the housing which has a peripheral flange. The inner peripheral face has a truncated conical or truncated pyramidal shape complementary to the shape of the peripheral edge of the opening of the case, the flange of the cover being designed to fit onto the peripheral edge of the opening and be held there by adhesion.