Ecological deep hole drilling is proposed in this paper. The ecological drilling means a cutting without coolant or minimum quantity lubrication (MQL). Under a cutting condition with a small amount of lubrication, the drills should be designed availably to control heat generation during cutting. An attempt is made on the development of innovative drills which are available for use under ecological cutting conditions. These drills were coated especially with a titanium aluminum nitride (TiAlN) film and a poly crystalline diamond layer. After TiAlN coating flutes of drills were lapped with diamond compounds . The result of studies on the process and application of the innovative drills was reported.