A compound sintered body contains cubic boron nitride particles and binder particles. The composite sintered body contains 40 vol% or more and 80 vol% or less of the cubic boron nitride particles. The binder particles contain TiCN particles. The composite sintered body shows a first peak belonging to a (200) plane of the TiCN particles in a range in which a Bragg angle 2¸ is 41.7° or more and 42.6° or less in an X-ray diffraction spectrum measured using a Cu-K± ray as a ray source. Assuming that a vertical axis y in the X-ray diffraction spectrum indicates diffraction intensity, and that a maximum value of a peak height of the first peak is defined as I max , a difference between a maximum value and a minimum value of Bragg angles 2¸ is 42.6° or less, the Bragg angles 2¸ being measured at two or more intersection points of a straight line y = I max /2 and the first peak.