In the fields of nuclear physics and elementary particle physics, accelerating cavities or structures are used to accelerate particles such as electrons, positrons, and protons to high energies. Mitsubishi Heavy Industries, Ltd. (MHI) has been developing various production technologies in order to provide the accelerating cavities and structures required for new research and experimental work. The C-band accelerator used in the X-ray free electron laser facility SACLA (the SPring-8 Angstrom Compact Free Electron Laser) was manufactured using one of these production technologies. Here, we describe our C-band accelerator products and the associated manufacturing technology.