An optical star coupler having a biconically tapered optical star coupler suspensively inserted in a protection tube and the method for manufacturing the same are disclosed, and the manufacturing method is that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby to form a twisting, fusing and pulling portion, and both ends of the protection tube are sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, naturally in the case of an optical star coupler using multi-mode optical fiber, particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing cost.