A catalyst casing-integrated exhaust manifold (manifold converter) includes an exhaust manifold section and a catalyst casing section. The catalyst casing section includes an approximately cylindrically-shaped casing main body holding a catalyst carrier, a conical part interconnecting the casing main body and the exhaust manifold section, and an outlet side shell connected to a downstream side of the casing main body. The exhaust manifold section and the catalyst casing section are formed by pressing a tailored blank by welding at least two metal blanks different in kind of materials and/or having different in thicknesses. In addition, the exhaust manifold section and the conical part of the catalyst casing section are formed of the same metal blank. The catalyst casing-integrated exhaust manifold and method of manufacturing same can reduce a number of components etc., thereby saving manufacturing cost.