To provide a thread winding device capable of preventing occurrence of sluffing.

A winding unit 10, while eliminating the threading defects of a thread feeding bobbin B1 around which is wound a thread Y that is spun using a fine spinning machine, winds a package P. The winding unit 10 comprises a thread storing device 100 which winds the thread Y from the thread feeding bobbin B1 and stores the wound thread. The thread storing device 100 comprises the following: a thread storing part 130 which stores the thread Y; and a winding part 140 which, while rotating, winds the thread Y around the thread storing part 130. The thread storing part 130 comprises the following: a thread storing body (belt outer side) 132F around which the thread Y is wound; and a drive pulley 134 which maintains an equidistant space between layers of the wound threads Y to be wound and supplies the thread Y that is wound around the belt outer side 132F from a winding side 130R to a releasing side 130F.