To provide a drill screw for a sheet used in a thin sheet.

This drill screw includes a shaft part 21 having a thread on the outer periphery: a head part 23 provided on one end side of the shaft part 21; and a drill blade 24 provided on the other end side of the shaft part 21. The drill blade 24 is formed thinner than the shaft part 21, and a tapered part 25 gradually increased in thickness as it goes from the drill blade 24 side toward the shaft part 21 side is provided between the other end side of the shaft part 21 and the drill blade 24. The edge of the hole penetrating from one surface side of the sheet to the opposite surface side by the drill blade 24 is projected to the opposite surface side of the sheet by the tapered part 25 by the drill blade 24, and while a root engaged with the thread of the shaft part 21 is formed on the inner periphery of the projected part, it advances to the opposite surface side of the sheet to achieve engagement.