A roughing end mill comprising: an end mill body which is rotatable around an axis; and a plurality of inserts (A, B, and C) which are placed on an outer circumference of the end mill body so as to have a predetermined distance apart from each other in the direction of the axis, wherein the plurality of inserts (A, B, and C) form a plurality of insert rows (S1, S2, S3, S4) which are provided in a circumferential direction of the end mill body, and at least the inserts excluding the inserts (B, C) at the tip of the distal end are positioned so as to be offset in the axial direction from each other in the different insert rows (S1, S2, S3, and S4) which are mutually adjacent in the circumferential direction, the inserts excluding the inserts (B, C) at the tip of the distal end are provided with waveform cutting edges which face towards an outer circumferential side of the end mill body, characterized in that the waveform cutting edges are formed by groove portions and raised portions which have a broadly circular arc shape made up of smoothly continuous concave curves and convex curves, one insert of one insert row and an insert of another insert row (S2, S3, or S4) which is offset therefrom in the axial direction among the inserts excluding the inserts (B, C) at the tip of the distal end are positioned such that the waveform cutting edges of each of these inserts make up a waveform cutting edge row whose phase is continuous on a rotation trajectory around the axis, and a plurality of these waveform cutting edge rows which have mutually different phases are formed on the outer circumference of the end mill body. an end mill body which is rotatable around an axis; and a plurality of inserts (A, B, and C) which are placed on an outer circumference of the end mill body so as to have a predetermined distance apart from each other in the direction of the axis, wherein the plurality of inserts (A, B, and C) form a plurality of insert rows (S1, S2, S3, S4) which are provided in a circumferential direction of the end mill body, and at least the inserts excluding the inserts (B, C) at the tip of the distal end are positioned so as to be offset in the axial direction from each other in the different insert rows (S1, S2, S3, and S4) which are mutually adjacent in the circumferential direction, the inserts excluding the inserts (B, C) at the tip of the distal end are provided with waveform cutting edges which face towards an outer circumferential side of the end mill body, characterized in that the waveform cutting edges are formed by groove portions and raised portions which have a broadly circular arc shape made up of smoothly continuous concave curves and convex curves, one insert of one insert row and an insert of another insert row (S2, S3, or S4) which is offset therefrom in the axial direction among the inserts excluding the inserts (B, C) at the tip of the distal end are positioned such that the waveform cutting edges of each of these inserts make up a waveform cutting edge row whose phase is continuous on a rotation trajectory around the axis, and a plurality of these waveform cutting edge rows which have mutually different phases are formed on the outer circumference of the end mill body.