PURPOSE: To mass-produce products of fixed quality at high working efficiency by bringing a crown forming member into close contact with inner peripheral face of a cylindrical mold, placing a mandrel coaxially with the mold, and after filling the mold with liquid rubber, hardening it by vulcanizing.

CONSTITUTION: A cylindrical mold 10 is fixed on a base stand 11 and covered airtightly by a cover 15 and a crown forming member 18 is brought into close contact with inner peripheral face of the mold 10. A mandrel 17 of fixed external form is installed coaxially in the mold 10. A feeding tube 12 that penetrates the base stand 11 is provided and extended into liquid rubber 14 contained in a rubber tank 13. A deairing tube 16 connected to a pressure reducing device is inserted into the cover 15. Pressure inside of the mold 10 is reduced through the deairing tube 16, and the mold 10 is filled with liquid rubber material 14 and then the liquid rubber material 14 is vulcanized and hardened at room temperature. Then, the mandrel 17 and crown forming member 18 are taken out from the mold, and the forming member 18 is removed. Thus, a crown type thermal fixing roller is obtained.