A helical blade cutter including multiple linear blades attached to an outer circumferential surface of a round body having an outer surface formed into a cylindrical circumferential surface. The blades tilt to a given helix angle α from a straight line on the outer circumferential surface parallel to a rotational central axis O. Blade attachment surfaces are formed on the outer circumferential surface of the round body at given intervals in the circumferential direction. The blade attachment surfaces tilt to an angle same as the helix angle α of the blade while tilting to a rake angle β in a direction of an elevation angle from a tangent to the outer circumferential surface. The blades are each attached to a blade attachment part through intervention of a chip holder that allows detachment of the blade.