To dispense with water content control of a resin in manufacturing and consideration for humidity conditions at a manufacturing site by using a phenol resin mixed with microcapsules containing hexamethylenetetramine therein as a binder, in a raw friction material consisting of a fiber base material, a binder, and a friction adjustment material.

In manufacturing a friction material, a phenol resin and hexamethylenetetramine are used as a thermosetting resin for a binder and a hardener respectively and the hexamethylenetetramine is mixed with the resin in a state that it is put in microcapsules so that the capsules are broken in thermosetting process to emit the hexamethylenetetramine as a gas. The capsule manufacturing method is that hexamethylenetetramine power is dispersed in cashew oil as a film formation material, its suspension 1 is fed to a drying chamber 2, sprayed in its upper part as droplets from a dispersing device 3, dried in a hot air 5 from a hot air generator 4, and sedimented in a separator 6 so that the capsule 7 coated with a cashew resin film is provided. This constitution can provide a friction material with a high rigidity and sufficiently hardened resin.