To reduce the bending of a rotary shaft by a heavy metal liner or mandrel by providing the means for supporting a near center place of the axial direction of the rotary shaft from the downside, in a filament winding forming device having the rotary shaft for rotating the metal liner or mandrel.

A metal liner 1 is fixed on a motor side rotary shaft 3 and a support rod side rotary shaft 4 at their caps 2. The motor side rotary shaft 3 and the support rod side rotary shaft 4 are supported by a lower support means 5 from the downside at the center part of the axial direction respectively and at the same time, pressed by an upper pressing means 6 from the upperside. Consequently, even when a heavy metal liner 1 is used, the motor side rotary shaft 3 and support rod side rotary shaft 4 are not bent largely. Therefore, the metal liner 1 can be rotated without off-centering and the vibration at the rotation time is lessened.