PURPOSE: To obtain a vulcanizable fluoroelastomer composition markedly improved in mold release without detriment to good sealability at high temperatures by mixing a fluoroelastomer with an organic peroxide, a polyfunctional cross-linking agentm a primary amine and a higher fatty acid ester.

CONSTITUTION: The composition is prepared by using a peroxide-vulcanizable fluoroelastomer, an organic peroxide, a polyfunctional cross-linking agent, a primary amine represented by the formula: RNH2 (wherein R is 14-22C alkyl), and a 30-70C higher fatty acid ester as the principal components. An example of a process for vulcanizing the above composition consists of milling the composition with open mill rolls or closed mill rolls, introducing the milled composition into a mold, subjecting the composition to the primary vulcanization under pressure and then subjecting the primary vulcanizate to the secondary vulcanization. As the conditions of the primary vulcanization, a temperature of 120-200°C, a vulcanization time of 1-180min and a pressure of 150kg/cm2 are generally adopted, and as the conditions of the secondary vulcanization, a temperature of 120-250°C and a vulcanization time of 0-48hr are generally adopted.