To improve the bonding strength between diamond and matrix composed of cemented carbide or cermet to a greater extent by specifying the content and size of diamond particles and also specifying the melting point and thickness of a coating layer which consists of one or more kinds selected from metals such as the group VIa elements, alloys of two or more elements among the group IVa, Va, and VIa elements or the like, and the carbides, nitrides, etc., of the group IVa, Va, and VIa elements, etc.

This hard member contains 3-50 vol.% of diamond particles and has a coating layer of one or more kinds selected from the following: metals consisting of the group VIa elements, Re, Os, Rh, Ir, and Pt; alloys consisting of two or more elements among the group VIa, Va, IVa, and VIa elements, Al, and Si; the carbides, nitrides, oxides, silicides, and borides of the above elements or solid solutions thereof. Moreover, the melting point of the coating layer is ≥1300°C and the average size D of the diamond particles is >100-3000 μm, and the thickness (d) of the coating layer is regulated so that it is ≤15 μm and the value K of ((0.5D+d)/0.5D)3 becomes ≥1.002. The hard member is manufactured by a sintering process under the condition that diamond is metastable.