PURPOSE: To provide a tool holder and the shank of a tool light in weight by forming themselves from a reinforced plastic material.

CONSTITUTION: A tool holder 4 is made of a reinforced plastic material - for example, thermo-setting resin reinforced with pump, natural fiber such as cotton, carbon fiber, glass fiber, etc., embodied in textile or splinters of their woven cloth. As such thermo-setting resins phenol resin, epoxy resin, etc., are exemplified in the form of a molding. These kinds of molding are excellent in not only in mechanical strengths such as anti-creep property and tensile strength but also the dimensional accuracy, coefficient of thermal expansion, anti- abrasivenss, heat resistance, oil resistance, and low electrostatic charging, being suitable for a material to build tool holder 4 and the shank 1 of a tool.