To provide a cutting insert, a cutting tool with the cutting insert attached to a tool holder, and a cutting method using the cutting tool, capable of performing polishing processing in a short period of time, suppressing fouling of a display part caused by chips and easily reading a display, in the cutting insert displaying information on a tool on the relief surface of the cutting insert.

The side surface of a plurality of side surfaces, provided with the relief surface includes a first flat part applied with the polishing processing and also continued to a cutting edge, a second flat part applied with the polishing processing and also separated from the first flat part, and a rough surface part not applied with the polishing processing and also positioned between the first flat part and the second flat part. The information on the cutting insert is displayed on the second flat part.