An
end mill (1) extending in the axial direction along a center axis (C), the
end mill (1) having a blade section (3) on the tip side of the
end mill (1), four or more groups of
cutting blades (7) being provided on the blade section (3) around the center axis (C), the
diameter dimension (D) of the rotational trajectory of the
cutting blades (7) around the center axis (C) being 3 mm or less, and the radial inner end of an end blade (71) being disposed at a distance from the center axis (C) in the radial direction. The rotation trajectory of the end
cutting edge (71) around the central axis (C) has a curved shape that protrudes toward the tip side in a longitudinal cross-sectional view along the central axis (C), and in the longitudinal cross-sectional view, the curvature
radius (R) of a convex curve formed by the rotation trajectory of the end cutting edge (71) is larger than the
diameter (D), and the
chip removal groove (4) has a groove
cut-off section (10). And a groove
cut-off section (10) which is positioned at the boundary between the rear end of the
chip removal groove (4) and the outer
peripheral surface (3b) of the blade section (3) and extends linearly, and the ratio (L / D) of the axial dimension (L) and the
diameter dimension (D) between the tip of the end blade (71) and the rear end of the
chip removal groove (4) is 2.0 or less.