A heat resistant drill screw suitable for drilling holes in a stainless steel sheet capable of preventing a delayed damage from occurring and providing a high corrosive resistance and a high tensile strength, comprising a drill part (4), a tapping screw part (5) arranged continuously with the drill part (4), a tightening screw part (6) arranged continuously with the tapping screw part, and a screw head part (3) for transmittingly providing a rotational force, characterized in that the drill part (4) and the tapping screw part (5) are formed of a high carbon chromium-based stainless steel, and the tightening screw part (6) including the screw head part (3) is formed of a nickel-based stainless steel.