To provide a rotary cutting tool with a sensor function capable of detecting the abrasion loss of a flank and the presence of small tracks even during machining and having sufficient sensitivity and reliability.

A rotary cutting tool which has a cutting edge area 11 provided with at least one cutting edge bank 4 and a fixed area 12 fixed to a tool rest of a machine tool is rotated around an axis to provide cutting with the cutting edge fringe 2 equipped with the cutting edge bank 4, wherein a coating of a linear conductive film guided from the fixed area 12 to the cutting edge area 11 is formed on the peripheral face.