To provide a machine tool system capable of realizing the cutting edge position measurement by a cutting edge position sensor without providing a transfer mechanism exclusive for the cutting edge position sensor.

The machine tool 1 is provided with a loader 2 and a cutting edge position detecting means 5 integrated with the loader 2. The loader 2 feeds and discharges a workpiece W to a workpiece support part 7 and moves the workpiece W to the cutting edge position sensor 28 mounted to the loader 2 and a tool measurement position P. A sensor positioning control means 31 controls so as to locate the cutting edge position sensor 28 at a tool measurement position P in a state that both of the loader 2 and the workpiece support part 7 support the workpiece W together.