PURPOSE: To prevent the cast defect in the thick part of a bearing holder in a cylinder block.

CONSTITUTION: In a casting device for the cylinder block, recessed parts 14p are formed on the thick part of the bearing holder in the cylinder block and chillers 26 for reducing the thickness of the bearing holder are provided. Then the chiller 26 has the structure, in which the projecting side from the forming surface in a die 13 can be adjusted during casting. For this purpose, the quantity of heat conducted from the molten metal through the thick part of the bearing holder and the chillers 26 is controlled and the solidifying speed of the molten metal in the thick part 14j of the bearing holder is controlled. Therefore, by making the solidifying speed of the molten metal in the thick part 14j of the bearing holder faster than the molten metal in skirt parts 14k of the cylinder block near the runner, the directive solidification is executed and the cast defect is difficult to develop.