To provide a friction base material with which judder resistance is improved while maintaining settling resistance by increasing porosity of a friction material, and optimizing an oil film on a surface of the friction material.

Porosity of a wet friction material is increased and judder resistance thereof is improved by compounding a volume contraction material, which achieves volume contraction by heating and which has elasticity, in a paper making step and subjecting the volume contraction material to contraction during a drying period in paper making and in curing a thermosetting resin. When lowering a ratio of the resin to be immersed or reducing a basis weight of a paper material in order to increase porosity, there has been a problem of increase in a settling amount in a conventional material. In the wet friction material, because the volume contraction material has elasticity, increase in the settling amount is suppressed. Thus, a structure in which an oil film is hardly produced in high-speed rotation is materialized due to increase in porosity, and the judder resistance thereof is improved without increase in the settling amount.