PURPOSE: To provide the bobbin chuck device of a spinning winder in which a chuck piece can be surely broken away from the hollow of a bobbin even if the encroaching amount of the chuck piece of a bobbin holder is made more.

CONSTITUTION: A spacer ring 21 and a chuck piece 22 are inserted into a rotary cylinder 51, and the chuck piece 22 consists of a first member 24 having first inclination surfaces 34, 35 and outer periphery surfaces 32, 33 in regard to a bobbin B and second members 23, 25 having a second inclination surface 28 engaged with the first inclination surfaces 34, 35 and an inner periphery surface 26 in regard to the rotary cylinder 51. These first and second members 23, 24, 25 are extendable/contractable diametrically by means of slits 30, 39, 40, and are connected to each other peripherally by means of connection portions 31, 41.