PURPOSE: To obtain an oil-free type heat fixing rubber roller superior in releasability by applying a coating layer of a prescribed compsn. to the outer circumference of a nonmagnetic metallic roll to form a heat fixing rubber roller.

CONSTITUTION: Polydimethylsiloxane blocked on the terminal OH group having a viscosity of 1,000W7,000cp as a base is mixed with a silicone oil having a viscosity of 500W5,000cp and an inorg. filler as uniformly as possible, and a cross- linking agent, such as organosilane compd. or siloxane compd., and a hardening catalyst, such as tin-type catalyst, are added to the mixture and mixed. The obtained paste-like compsn. is spread on all width of the outer circumference of a nonmagnetic metallic roll and hardened. The obtained oil-free type heat fixing rubber roller is superior in releasability.