This sintered body has a first material, a second material, and a third material. The first material is a cubic boron nitride. The second material is a compound including zirconium. The third material is an aluminum oxide which includes fine aluminum oxide. The sintered body has a first region in which the fine aluminum oxide is dispersed in an amount of 5% to 50% by volume in the second material. Along any straight line in the first region, an average value of a continuous distance occupied by the fine aluminum oxide is 0.08 μm or less, and a standard deviation of the continuous distance occupied by the fine aluminum oxide is 0.1 μm or less.