PURPOSE: To ensure a construction with use of a small number of definite bricks by forming the construction in which two fundamental definite bricks are provided and the first fundamental definite brick provides a minimum spherical radius with an inclination of an internal surface with respect to an outer surface.

CONSTITUTION: A lining 23 comprising sized bricks is provided on an outside lining 22. An internal surface having sizes a1, c1, h and an external surface having sizes b1, d1, h form an angle a therebetween. Hereby, there is provided a radius r indicative of an interval between a virtual intersection line between the internal and external surfaces and a high temperature side surface. The radius r is a characteristic amount of a sized brick system whereby a spherical surface radius rgi obtained on a high temperature side of the lining 23 is also ensured. When there are added brick height h and the thickness of the outside lining 22 to the spherical surface radius rggi there is ensured a minimum value of a spherical surface radius R of a steel outer enclosure 21 made possible with the brick system. Hereby, a lacked spherical surface and a circular arc ring surface having an arbitrary radius within a specific limit can be constructed with a small number of sized bricks substantially without causing any gap.