A flanged hollow structure capable of increasing a structural integrity by preventing cracking due to thermal fatigue from occurring around a flange, comprising the annular flange fixed to the outer peripheral surface thereof causing a temperature difference in the direction of plate thickness thereof, wherein the annular flange is characterized in that a metal material having a linear expansion coefficient larger than the linear expansion coefficient of the metal material around the inner edge of the annular flange is provided along the outer edge of the annular flange.