An end mill comprising: an end mill body including a rotation axis (O); a cutting edge portion located at a front end side of the end mill body ; a proximal end portion located at a rear to the cutting edge portion ; a shank portion located at a rear to the proximal end portion ; two or more end cutting edges located at the front end side of the cutting edge portion ; peripheral cutting edges located at a rear to the end cutting edges of the cutting edge portion and extending to the proximal end portion ; and chip discharging flutes each located between two peripheral cutting edges and helically extending from the front end side to the proximal end portion , wherein each of a plurality of the peripheral cutting edges and each of a plurality of the chip discharging flutes are alternately located from the front end side to a side of the proximal end portion , and a distance (t, ta, tb, tc) between a deepest position (p, pa, pb, pc) of the chip discharging flute and the rotation axis (O) is set equal among the respective chip discharging flutes in a cross section taken along the rotation axis (O) of the end mill body , the chip discharging flute comprises a first region located at a side of the peripheral cutting edge and including the deepest position (p, pa, pb, pc), a second region located at a side of a heel opposite to the peripheral cutting edge , and a boundary located between the first region and the second region ; and a distance (uc) from the rotation axis (O) to the boundary located at a most proximal end portion side is larger than a distance (ua) from the rotation axis (O) to the boundary located at a most front end side, the first region comprises a first trace located in the same direction as an advancing direction of the chip discharging flutes , and the second region comprises a second trace located in a direction which intersects with a rearward advancing direction of the chip discharging flutes at an acute angle. an end mill body including a rotation axis (O); a cutting edge portion located at a front end side of the end mill body ; a proximal end portion located at a rear to the cutting edge portion ; a shank portion located at a rear to the proximal end portion ; two or more end cutting edges located at the front end side of the cutting edge portion ; peripheral cutting edges located at a rear to the end cutting edges of the cutting edge portion and extending to the proximal end portion ; and chip discharging flutes each located between two peripheral cutting edges and helically extending from the front end side to the proximal end portion , wherein each of a plurality of the peripheral cutting edges and each of a plurality of the chip discharging flutes are alternately located from the front end side to a side of the proximal end portion , and a distance (t, ta, tb, tc) between a deepest position (p, pa, pb, pc) of the chip discharging flute and the rotation axis (O) is set equal among the respective chip discharging flutes in a cross section taken along the rotation axis (O) of the end mill body , the chip discharging flute comprises a first region located at a side of the peripheral cutting edge and including the deepest position (p, pa, pb, pc), a second region located at a side of a heel opposite to the peripheral cutting edge , and a boundary located between the first region and the second region ; and a distance (uc) from the rotation axis (O) to the boundary located at a most proximal end portion side is larger than a distance (ua) from the rotation axis (O) to the boundary located at a most front end side, the first region comprises a first trace located in the same direction as an advancing direction of the chip discharging flutes , and the second region comprises a second trace located in a direction which intersects with a rearward advancing direction of the chip discharging flutes at an acute angle. <EOS>