Corner cutting edges (7 and 8) each having a side portion connected to a minor cutting edge and curved in the same direction as that in which the minor cutting edge is curved are formed on opposite sides of the minor cutting edge (6) of an indexable cutting insert for milling including a major cutting edge (5) formed of a ridge formed by an intersection of a rake face and a flank face and the minor cutting edge (6) for finish machining curved in a convex manner when viewed from a direction perpendicular to the flank face, and the minor cutting edge (6) continues to the major cutting edge (5) via the corner cutting edges (7 and 8).