Cubic boron nitride sintered body and coated cubic boron nitride sintered body

A cubic boron nitride sintered body comprising cubic boron nitride and a binder phase, wherein

• a content ratio of the cubic boron nitride is 10.0 volume % or more and 60.0 volume % or less and a content ratio of the binder phase is 40.0 volume % or more and 90.0 volume % or less based on 100.0 volume % of the entire cubic boron nitride sintered body,
• the binder phase includes a Ti compound phase, an Al compound phase, and a W element-containing phase,
• a content ratio of the Ti compound phase is 60.0 volume % or more and 92.0 volume % or less, a content ratio of the Al compound phase is more than 0.0 volume % and less than 15.0 volume %, and a content ratio of the W element-containing phase is 5.0 volume % or more and 30.0 volume % or less based on 100.0 volume % of the entire binder phase,
• the W element-containing phase contains at least one selected from the group consisting of W2B and WB, and
• I2/I1 is 0.03 or more and 0.60 or less, where I1 denotes an X-ray diffraction peak intensity of a (111) plane of the cubic boron nitride, and I2 denotes a sum of X-ray diffraction peak intensities of a (211) plane of W2B and a (110) plane of WB in the binder phase.