The present invention is intended to prevent the residual stress from remaining in an apex. An apparatus for automatically assembling a bead apex according to the present invention comprises: a means for joining both the longitudinal ends of a strip apex having a triangular section with one short side and two long sides and a specified length to each other, and for forming the strip apex in a cylindrical body such that the long sides become the inner and outer peripheral surfaces; a means for forming the cylindrical body into a disk-like shape such that the short side becomes the inner peripheral surface and the long sides become the axial end surfaces; and a means for joining the inner peripheral surface of the disk-like apex to the outer peripheral surface of a bead ring.