To add a silencing function in a tail pipe part and to allow wide range selection for the discharging direction of emission gas.

In a muffler for a small size engine, an exhaust outlet part is constructed of a pipe 22 and a tail pipe 23. In the pipe 22, which passes through an exhaust side chamber of a muffler main body 21 horizontally in the width direction with its both sides protruded from the muffler main body 21 and is airtightly fixed, both ends are opened, and several exhaust passage holes 22a are provided in the center part. In the tail pipe 23, which is inserted into the pipe 22 so as to be fastened and fixed in both ends of the pipe 22, the outside diameter, in which a clearance constituting an exhaust passage in the diameter direction can be formed, is provided, one end part is closed, the center part is provided with several exhaust passages 23a, and the other end is opened. In this way, a silencing function is additionally provided in the exhaust outlet part, and the exhaust direction can be selected from two directions on both sides.