Cutting tool

A cutting tool having a rake face, a flank face continuous to the rake face, and a cutting edge formed by a ridgeline between the rake face and the flank face, the cutting tool comprising:

• a base material having a first face on a side of the rake face and a second face on a side of the flank face;
• and
• a diamond layer covering the first face and the second face,
• the first face including
• a first top face continuous to the second face, and
• a second top face continuous to the first top face and disposed such that the first top face is sandwiched between the second top face and the second face, wherein
• an angle formed between the first top face and the second top face is a negative angle in a cross section perpendicular to the cutting edge,
• the rake face has a first rake face portion and a second rake face portion,
• the first rake face portion is located between the flank face and the second rake face portion,
• in the cross section perpendicular to the cutting edge, an angle formed between the first rake face portion and the second rake face portion is a negative angle,
• the flank face has a first flank face portion and a second flank face portion continuous to the first flank face portion,
• the first flank face portion is continuous to the first rake face portion,
• the second flank face portion is inclined with respect to the first flank face portion,
• a plane passes through a boundary between the first top face and the second face,
• the plane is parallel to the second top face,
• the plane intersects the first flank face portion, and
• in a direction perpendicular to the second top face, a thickness of the diamond layer at a boundary between the first top face and the second face is larger than a thickness of the diamond layer at a boundary between the first top face and the second top face.