To provide a glass fiber unwinding device capable of unwinding glass fiber so that remaining winds around a bobbin are not left.

Motors 16, 42 and 45 are driven, a rubber adhesive is applied to a glass code 1 wound around a bobbin 11 at a creel side through an immersion part 20 and a dry part 30, and then the glass code 1 is wound by a winding bobbin 44. When all of the glass code 1 is unwound from the bobbin 11, a guide roll 14 depresses a cushion cylinder 17 downward by tension of the glass code 1 to move downward. This movement is detected by a reed switch 18. Thus, high air pressure is supplied to each brake 11b, 41b and 44b so that the bobbin 11, a feed roll 15, a take-off roll 41 and the winding bobbin 44 are stopped.