A composite sintered body according to the present invention contains at least cubic boron nitride and a binder Cubic boron nitride has a continuous structure as a result of bonding of a plurality of cubic boron nitride particles to each other. The binder has a continuous structure as a result of bonding of a plurality of binder particles to each other, that are present in a region except for a bonding interface where the cubic boron nitride particles are bonded to each other.
