The objective of this study was to investigate the possibility of the triboelectrostatic separation of unburmed carbon from coal fly ash using a ejector-tribocharger with a SUS 304 for fly ash recycling. Experiments were carried out to study the effects of the rate of motive air, the particle density at ejector mixing section, the carbon content in fly ash fed, the relative humidity of atmospheric air inhaled, the flux temperature of mixture of air and particle, and the applied voltage between the two parallel electrodes on the charge-to-mass ratio and electrostatic separation efficiency. The charge-to-mass ratio and electrostatic separation tests using this separator performed by a fly ash sample with 7,5% carbon content. The test results of charge-to-mass ratio and separation efficiency found to be strongly affected by the change of the relative humidity of atmospheric suction air and the size distribution of fly ash than other parameters. Test results of triboelectrostatic separation efficiency indicated also that a fly ash of 7.5% LOI could be processed into 3.0% LOI product over a recovery of 80%.