Seizure resistance and wear resistance of CuBiIn copper-alloy sliding material are enhanced by forming a soft phase of as pure as possible Bi. Mixed powder of CuIn cuprous alloy powder and CuBi containing Cu-based alloy powder is used. A sintering condition is set such that Bi moves outside particles of said CuBi containing Cu-based powder and forms a Bi grain-boundary phase free of In, and In diffuses from said CuIn containing Cu-based powder to said CuBi containing Cu-based powder.

A sliding member includes a base layer that includes soft particles made of a soft material deposited in a matrix and a soft layer made of a soft material. The soft material is softer than the matrix, the soft layer is formed on a surface of the base layer, and a maximum epitaxial index of the soft particles as the boundary portion of the sliding member is equal to or less than 10% and greater than 0%. The epitaxial index of a soft particle at the boundary portion is a ratio of: a portion of a length between a first endpoint and a second endpoint of a soft particle where an edge of the boundary portion is not visible within an area less than 1 m from the length between the first endpoint and the second endpoint, to the length between the first endpoint and the second endpoint.

A sliding member includes a base material and an alloy layer that includes Cu as a main component and Bi and having a sliding surface formed on a side opposite to the base material. The alloy layer has a first region and a second region. The first region is set to a region taking up 30% of the thickness of the alloy layer which is from an interface in contact with the base material toward the sliding surface. The second region is set to a region taking up 10% of the thickness of the alloy layer which is from the sliding surface toward the base material. A larger number of Bi phases having larger cross-sectional areas are distributed in an arbitrary observation cross section as Bi phases included in the second region compared to Bi phases included in the first region.