The present invention aims at providing a connecting method of optical devices capable of suppressing a periodic wavelength dependence loss and the like, due to the inter-polarization-mode interference caused when connecting a plurality of optical devices by using an optical path having a polarization-preserving characteristic, and an optical apparatus applied with the connecting method. The outer peripheral surface of the envelope-like membrane forming the spiral wound type membrane component is covered with a sheath member, and anti-telescopic members are mounted on both end surfaces of the envelope-like membrane respectively. Wherein the slider has an angled side inwardly angled at a side of the first sliding portion thereof and the arm has a straight side for restricting a rotation angle thereof.