To provide a method of manufacturing a cylindrically extruded material by which the cylindrically extruded material excellent in the accuracy of an inside diameter is manufactured at high productivity.

This manufacturing method is provided with a step where the cylindrically extruded material having a nozzle hole is prepared and a step where a bar-like extruding tool 1 is forced into the nozzle hole from the top side and straightened by widening the inner peripheral surface of the nozzle hole with the tool 1. The tool 1 has a plurality of projecting parts 10-13 which are projected in the radial direction and also arranged in the axial direction and are provided so that the amount rn (n=10, 11, 12, 13) of projection is enlarged from the top side of the tool 1 toward the root side.