A particle having a rough surface and obtained from a particle (A) having grafted on the surface thereof a polymer having first functional groups and particles (B) having grafted on the surface thereof a polymer having second functional groups reactive with the first functional groups, by uniting the particle (A) with the particles (B) through chemical bonds between the first functional groups and the second functional groups. In this particle with a rough surface, the core particle has been tenaciously bonded to the protruding particles. Because of this, even when the protruding particles have an increased particle diameter, the protruding particles can be prevented from readily shedding from the core particle.