On the perimeter of a head (14) that is bonded on one end of the shank (12) of a T-shaped cutter, multiple end cutting edge sections (16) with a cutting edge (16a) on the tip side of the T-shaped cutter (10) and multiple upper edge sections (18) with a cutting edge (18a) on the base end side are disposed alternating in the circumferential direction of the T-shaped cutter. The cutting edges (16a, 18a) of the end cutting edge sections (16) and the upper edge sections (18) form an integral structure with the shank (12) and the head (14).