A cBN sintered body tool has the following feature. In at least one cross sectional surface of the cBN sintered body tool taken along a plane perpendicular to a joining surface having the largest area in joining surfaces between the cBN sintered body and the joining layer, a point C and a point D are assumed to represent points away by ¼ of the length of a line segment connecting a point A and a point B shown in a figure. A value obtained when an area of a region surrounded by a line segment connecting the point C and the point D, the first cBN particle, the second cBN particle, and the binder phase is divided by the length of the line segment connecting the point A and point B to each other is 0.14-0.6 μm.