An exhaust chamber is disposed in an exhaust passage through which exhaust gas from an engine passes. The exhaust chamber includes: an inner case having a chamber expansion region therein; and an outer case configured to cover a portion of the inner case. The inner case has a first inner case half and a second inner case half which are obtained by division into two parts, and is formed by the first inner case half and the second inner case half being joined to each other at an inner joining portion. The outer case has a first outer case piece and a second outer case piece which are spaced from each other. The first outer case piece and the second outer case piece are each joined to a portion, on an outer surface of the inner case, which portion is different from the inner joining portion.