Abstract: An object of the present invention is to provide a thread coupled lens barrel which can be manufactured easily by using inexpensive members and in which both parts in the thread engagement without any gap or back-lash in the thread engagement site can be aligned with high precision along a center axis line or an optical axis. Provided is a thread coupled lens barrel having a thread engagement site, characterized in that an elastic synthetic resin tape is disposed between a female thread and a male thread in said thread engagement site and a state of thread engagement is secured by a fixing screw. Also provided is another thread coupled lens barrel having a thread engagement site, characterized in that an elastic synthetic resin tape is disposed between a female thread and a male thread in said thread engagement site and a thread engaged rotation between said female thread and said male thread relative to each other in said thread engagement site is made possible.