To regulate the lubricating oil feeding amount to a bearing adequately without stopping the generating operation, when an unstable vibration is generated to some bearing of plural bearings formed in parallel.

In a rotary electric machine bearing oil piping oil amount regulating device which has a piping to feed and discharge the lubricating oil of a slide bearing to support the rotator of a rotary electric machine or a prime mover through the lubricating oil, and regulates the oil amount adequately, an orifice 3 is provided in an oil feed pipe 2 to feed the lubricating oil to the slide bearing 10, and an oil amount increasing means 40 to bypass connect the orifice 3, an oil discharging pipe 5 to discharge the lubricating oil from the slide bearing 10, and an oil amount decreasing means 60 to bypass connect the oil feed pipe 2, are provided.