A chuck device that allows easy attachment of a clamping target component and can provide powerful and highly reliable clamping includes a main body including a metal core part and an annular space coaxial with and formed around the metal core part; a rubber elastic body fitted in the annular space of the main body such that there is a pressure chamber between a circumferential wall that defines the annular space and the rubber elastic body, and a clearance for allowing a tubular clamping target component to be inserted between the rubber elastic body and the metal core part; and a passage for introducing a fluid to the pressure chamber, wherein the rubber elastic body is deformed to expand toward the metal core part by a pressure of a fluid introduced to the pressure chamber via the passage so that a tubular clamping target component that is attached to the metal core part is clamped by the metal core part and the rubber elastic body that has deformed to expand.