PURPOSE: To promptly further surely polish a fine hole, by dispersedly holding abrasive grains in fluidized media passing through the through hole of a workpiece and applying an ultrasonic vibration to the media so that the media decrease the viscosity improving the fluidity.

CONSTITUTION: Abrasive grains 4 of diamond or the like, for instance, of about #1000 and media 5, for instance, of silicone rubber or the like, having fluidity and dispersedly holding said abrasive grains, are allowed to pass through a fine hole 1 from its one opening of a workpiece 2, held to a holding part 3, and an ultrasonic vibration is applied to the holding part 3 from an ultrasonic wave applying part 7. Consequently, a device uniformly disperses the abrasive grains 4 in the media 5 while softens a binding material, for instance, silicone rubber by generating heat. As a result, the media 5 remarkably improve the fluidity by substantially decreasing the viscosity resistance. Accordingly, the device, which allows the media 5 to smoothly pass through in the fine hole 1 generating no blocking, enables the fine hole 1 to be high accurately further high efficiently polished.