An exhaust muffler for silencing exhaust gases, introduced from a first side, and then discharging them to a second side opposite to the first side, includes a silencing chamber forming structure having first, second and third chambers disposed sequentially from the second side to the first side, an inlet tube to communicate the outside on the first side with the first chamber after having sequentially passed through the third and second chambers, an outlet tube to communicate the second chamber with the outside on the second side after having passed through the first chamber, a first communicating passage communicating between the first and second chambers, and a second communicating passage communicating between the second and third chambers. A peripheral wall portion of the inlet tube, positioned in the third chamber, is formed with a vent hole to communicate a space within the inlet tube with the third chamber.