Drill

A drill that exhibits improved drill-hole depth precision is provided. Said drill, which uses a tool (T) mounted to a main shaft (16) to drill a countersunk hole (Wh) into a workpiece (W), is provided with the following: a pressure foot (17) that presses on the surface of the workpiece (W) and suppresses vibration thereof; and a displacement sensor (18) that measures the distance (L), in the axial direction of the main shaft (16), between the pressure foot (17) pressing on the workpiece (W) and the end face (16a) of the main shaft (16), which is set to a prescribed reference distance (Lo). The axial position of the main shaft (16) is corrected using a correction distance (ΔL), i.e. the difference between the distance (L) measured by the displacement sensor (18) and the reference distance (Lo). After the main shaft (16) is set to the reference distance (Lo), the main shaft (16) is moved in the axial direction thereof in accordance with the depth of the countersink part (Whb) of the countersunk hole (Wh) and the tool (T) is used to drill the hole.