A regenerative refrigerator includes a regenerator disposed in a flow passage of working gas generating a cold thermal mass, the regenerator being loaded with a regenerative material to accumulate cold thermal energy from the cold thermal mass in the working gas, wherein the regenerative material is a sintered body made of a fiber material, and a diameter of the fiber material disposed at a low-temperature end of the regenerator is smaller than a diameter of the fiber material disposed at a high-temperature end of the regenerator.