PURPOSE: To provide a chuck device which can reliably support a work in a stable condition in response to an inside diameter of the work over a wide range and can freely rotate the work in a supporting condition.

CONSTITUTION: In a chuck device 10, three rotary shafts 24 are arranged on the same circumference, and a work support part 28 is integrally arranged on the respective rotary shafts 24 through an arm 26. Therefore, when the rotary shafts 24 are reciprocatively rotated by a rotary actuator 16, the work support part 28 supports an inner peripheral surface of a work through the arm 26 by being reciprocatively and horizontally rotated in the mutually contacting-separating direction with the rotary shafts 24 as the center. Therefore, the device can cope with the work having an inside diameter over a wide range, and the work can also be reliably supported in a stable condition.