To provide a friction material appropriately usable as a brake material and a clutch material and excellent in bonding durability by protecting the iron plate of the baking plate under the copper film from rust formation to thus prevent a reduction in bonding strength and peeling of the lining material even with use under an environment with saline moisture in a sintered friction material where a metal lining material using a metallic material as the matrix mixed with a friction control material, a lubricant and the like is diffusion- bonded through sintering to a baking plate of metal via a copper coating.

A metal lining material comprises an outer lining material with a porosity of 10% or more and an inner lining material with a porosity of 8% or less, wherein the inner lining material is interposed between the outer lining material and a copper film surface of a backing plate. The outer lining material and the inner lining material are preferably a copper lining material.