PURPOSE: To wind large quantity of filaments, store the filaments and mechani cally and stably form filament windings by winding the filaments so as to alternately advance in one direction and the other direction of the axial direc tion relative to a center winding part by pitch of about three times and a half as long as the diameter of a filament every time the filament is wound at a turn.

CONSTITUTION: A bobbin 82 is provided with a flange 84 formed at a right angle with a shaft. A value of pitch P of a groove 90 fixing the location of a filament 52 of a first layer is made almost three times and a half as long as the diameter of the filament 52. The filament 52 is wound on a center winding part 88 by using the groove 90. On the above, the filament 52 is wound between lower side filaments so as to advance in the left and right directions in accordance with numbers 8th to 16th. As a result, the layer of the filament 52 of the upper side is located on a location sunk by a length corresponding to a radius of the filament 52 on the layer of the filament 52 of the lower side and the locations between filaments 52 each other are stably maintained. In this case, the filament 52 is advanced by two times as long as pitch P for a winding of a Fig. by a winding part 88.