In electrical discharge machining (EDM), it is well known that removal rate and surface roughness are improved with ultrasonic vibrated tool. However, it is difficult in an actual machining to keep resonant conditions with a tool electrode of various sizes and materials. In this study, a new supporting method of an ultrasonic transducer and the vibration transmission method of a tool electrode are examined. EDM and abrasive machining were performed with ultrasonic vibrated tool. In the machining of steel plate, the machining speed was improved by five times compared with conventional finish EDM. The tool electrode excited by ultrasonic vibration is also applied to diamond abrasive grinding process for removing carbon layer on insulating ceramics after EDM with an assisting electrode. Mirror surface of silicon nitride ceramics can be achieved through the grinding process.