To enhance the dusting characteristic and outgassing characteristic of a resin cage for a bearing, while permitting mass-production of the cage through injection molding, and assuring excellent lubricity and long life.

The resin cage 4 for a bearing is injection molded using a material obtained by selecting a thermoplastic resin excellent in outgassing characteristic, and adding appropriate amounts of proper reinforced monofilaments and lubricating components thereto. This permits the cage to be mass-produced and show stable bearing performance while maintaining a vacuum environment over a long period of time.