Indexable milling cutting insert

The present invention aims to improve a milling cutting tool machining surface, the cutting tool having a cutting edge for finishing sub. Minor cutting edge is provided (3) having a corner portion: two circular cutting edge portions (3a, 3a), which (2) is connected to the major cutting edge; and a straight cutting edge portion (3b), which is provided two circular cutting edge portion (3a) between. When viewed in the thickness direction of the cutting tool, the following conditions are satisfied: 0.05TA≤L1≤0.4TA, 0.1L1≤L≤0.5L1, and h≤15μm, wherein, the TA is the inscribed circle within the respective main cutting edge (2) radius, L1 is the minor cutting edge (3) the length in the longitudinal direction of the straight cutting edge portion (3b) is, L is the length of the straight cutting edge portion (3b), h is the height of the minor cutting edge (3).