To protect grease from high temperature unnecessarily generated by gear teeth by filling grease in a gear chamber in a power tool with an angle drive device.
The angle drive device 13 is provided with a gear chamber 30 storing lubricating grease therein, a pinion 16 connected to a motor 11, and a bevel gear 17 connected to an output shaft. An immovable wall element 24 arranged adjacent to a practical part of teeth of the bevel gear 17 makes most part of lubricating grease in the gear chamber 30 directly contact the teeth of the bevel gear and forms a grease screen. A grease moving element 33 is movably guided along a circle passage formed with a groove 32 on an end wall 31 of the housing 10 below the bevel gear 17. A coupling device 34 is attached to the bevel gear 17 and is combined with the grease moving element 33.