An object is to provide a cutting insert for milling that has a minor cutting edge for wiping to achieve improved machined surface quality. A minor cutting edge 3 at a corner includes two circular cutting edge portions 3a and 3a joined to major cutting edges 2 on both sides of the corner and a straight cutting edge portion 3b located between the two circular cutting edge portions 3a. The cutting insert satisfies the following conditions: 0.05TA≦L1≦0.4TA, 0.1L1≦L≦0.5L1, and h≦15 μm, where TA is the radius of a circle inscribed inside the major cutting edges 2 as viewed in the thickness direction of the cutting insert, L1 is the length of the minor cutting edge 3 in the longitudinal direction of the straight cutting edge portion 3b, L is the length of the straight cutting edge portion 3b, and h is the height of the minor cutting edge 3.