PURPOSE: To produce a thin sheet having apertures at a high speed by making the peripheral width of a nozzle larger than the width of pattern grooves on the outside peripheral surface of a roll and coating a material which is not wetted by a molten metal to the surface except the pattern grooves of the outside peripheral surface of the roll.

CONSTITUTION: A pressurized gas is introduced into the upper part of the nozzle to pressurize the surface of the molten metal so that the molten metal 08 is extruded from a slot 06. The molten metal 08 extruded from the slot 06 is poured only into the pattern grooves 05 and does not stick to the outside peripheral surface except the grooves. The liquid metal is sheared by the relative motion of the projecting parts of the roll grooves and the inside surface of a contact shoe and the product apertures are formed. The member produced in the above-mentioned manner is cast under the pressure with the substantial head and is therefore free from casting defects.