A chuck device capable of efficiently changing a welding tip and nozzle. The chuck device includes a rotatable chuck base, an engagement part fixed to the chuck base so as to rotate integrally with the chuck base and can engage an engagement surface of the welding tip, the engagement part allowing the welding tip to rotate with the chuck base when the chuck base is rotated while engaged with the engagement surface, and a plurality of fingers provided to the chuck base to be openable and closable and can hold the welding tip and the nozzle, the plurality of fingers being capable of moving in directions approaching and separating from the engagement part.