A sliding member which ensures a low coefficient of friction and a high degree of wear resistance, and is suitable for use in a bearing, mechanical seal, etc. It comprises a ceramic or metallic base, a diamond film formed on a surface of the base and having a rugged surface defining concavities, and a soft metal filling those concavities. When a relative sliding motion is made between it and a mating part formed from a hard material, only a low coefficient of friction occurs and the abrasive wear of the mating part is greatly reduced. It can maintain its high wear resistance for a long time even when it is used in a dry mode not involving the use of any lubricating oil, coolant, etc., since the diamond film does not undergo any change under heat to graphite having a lower degree of hardness.