For machining micro hole and micro cavity in ceramics, a manufacturing methods based on green machining have been systematically researched. The micro tool was prepared on-machine by micro electrical discharge machining (EDM). The tool size for micro hole drilling was determined based on extensive experimental results of the sintering shrinkage ratio and the gap caused by the removed ceramics particles between the tool and the workpiece to achieve the desired hole diameter. The tool path design was based on the tool size, the shrinkage ratio and the gap which is different from that in micro hole drilling. Micro holes with diameter of 100μm and micro cavities with upper surface size of 500μm×500μm was machined in ceramics successfully by this method. The final size error was controlled less than 2.25% in micro hole drilling and less than 2% in micro cavity generation.