An exhaust manifold has a structure such that an end portion of a
collecting section where pipes connected to respective cylinders of an
engine are collected is connected to an exhaust pipe via a joint tube
member. The joint tube member is constituted by an upper joint portion
and a lower joint portion, and cut-out grooves are formed on both joining
portions of the upper joint portion or the lower joint portion. With the
cut-out grooves, a partition plate is engaged to be positioned, and in
this state, the partition plate is fixed to the upper joint portion or
the lower joint portion.