Provided is an endless operation cord that is easy to replace. The present invention provides an operation cord including: a main cord having one and the other ends; a first coupling part disposed at the one end; and a second coupling part disposed at the other end. The first and second coupling parts can be coupled together directly or via a coupling member and can be coupled or uncoupled by means of a relative rotation between the adjacent coupling parts or between the adjacent coupling parts and coupling member or a relative movement in a direction other than a length direction of the main cord between the adjacent coupling parts or between the adjacent coupling parts and coupling member.