A composite diamond body includes a diamond base material and a stable layer disposed on the diamond base material. The stable layer may have a thickness of 0.001 μm or more and less than 10 μm, and may include a plurality of layers. A composite diamond tool includes the composite diamond body. There are thus provided highly wear-resistant composite diamond body and composite diamond tool that are even applicable to mirror-finish planarization of a workpiece which reacts with diamond to cause the diamond to wear.

A composite diamond body includes a diamond base material and a stable layer disposed on the diamond base material. The stable layer may have a thickness of 0.001 m or more and less than 10 m, and may include a plurality of layers. A composite diamond tool includes the composite diamond body. There are thus provided highly wear-resistant composite diamond body and composite diamond tool that are even applicable to mirror-finish planarization of a workpiece which reacts with diamond to cause the diamond to wear.