A silencing apparatus for a vehicle includes: a muffler (1; 20; 30; 40) having a flattened sectional shape; an inlet pipe (7; 26; 36; 46); an outlet pipe (8; 27; 37; 47); and at least one partition plate (2, 3; 21, 22; 31, 32; 41, 42) that divides the inside of the muffler (1; 20; 30; 40) into a plurality of sound-deadening chambers. Each of the at least one partition plate (2, 3; 21, 22; 31, 32; 41, 42) has at least one communication hole. Within the muffler (1; 20; 30; 40), at least one among an opening of the inlet pipe (7; 26; 36; 46), an opening of the outlet pipe (8; 27; 37; 47), and the at least one communication hole is disposed at a position that is apart by a length equal to a half of the width of the muffler (1; 20; 30; 40) from one end of the muffler (1; 20; 30; 40) in the width direction thereof, and at least one among them is disposed at a position that is apart by a length equal to a quarter of the width from one end of the muffler (1; 20; 30; 40) in the width direction.