A transmission apparatus for an automobile or the like includes: a transmission gear mechanism including, therein, a speed-reducing small gear at an axial one side of an intermediate shaft; a final driving mechanism including, therein, a speed-reducing large gear at an axial one side of an axle; a casing including: a first chamber; a second chamber; a first inner surface; a second inner surface; and a case rib; and a wall which is positioned between the first inner surface and the end surface of the speed-reducing large gear that faces the first inner surface; the wall including: a lower portion; and an edge portion, and the wall covering, at a short distance away, the end surface of the speed-reducing large gear that faces the first inner surface.