A muffler system with a muffler in one aspect of the present disclosure includes an outer wall, and a first separator and a second separator that partition a muffling space. An attachment member is arranged on an outer surface of the outer wall, and a muffler pipe to communicate with the muffling space is arranged to pass through an attachment member hole in the attachment member. The outer surface of the outer wall includes a first area and a second area. The first area is located between a first end of the muffling space and the first separator, and the second area is located between a second end of the muffling space and the second separator. The attachment member is welded to the first and second areas of the outer surface of the outer wall.