To provide a method of manufacturing a superconducting acceleration cavity capable of manufacturing a superconducting acceleration cavity of high quality at low costs with compact device structure.

This method manufactures an acceleration cavity 1 for manufacturing an acceleration cavity (a superconducting acceleration cavity) 1 by arranging a plurality of half cells 5, which respectively has opening parts in both ends in the axial direction, in the axial direction L, and bonding the opening parts to each other by welding. Bonding of the half cells 5 is performed by welding, using a laser beam, from the inside of the acceleration cavity 1 formed into a vacuum atmosphere.