To provide a monitoring method of an fat and oil supply condition of lubricant, in which a fat and oil supply condition supplied into lubricated position such as a bearing of a rotary machine can be inexpensively and easily monitored near each lubricated position.

A sensor is attached to equipment requiring lubrication fat and oil supply or fat and oil supply piping connected to the equipment so as to monitor the fat and oil supply condition to the equipment. The sensor is set to be subjected to bending deflection due to the flow of lubricant at fat and oil supplying, and the strain generated with the sensor by bending deflection owing to the flow of the lubricant is transformed into an electric signal. Based on the electric signal, the number of lubrication times to the equipment requiring the fat and oil of the lubricant is counted. When the counted number of the lubrication time is smaller than the previously set time of lubrication in an regular time, it is determined that the fat and oil supply condition is abnormal.