PROBLEM TO BE SOLVED: To provide radioactive materials without using a nuclear reactor.SOLUTION: Radioactive materials including at least either a first radionuclide obtained by making a negative muon enter a target nuclide to cause muon capture reaction, or a second radionuclide which is at least one kind out of descendant nuclides generated after radioactive decay of the first radionuclide, are provided. Besides, a production method of the radioactive materials including a muon irradiation step in which the first radionuclide is obtained by making the negative muon enter the target nuclide to cause the muon capture reaction, is provided.
