This manual is published for the following purposes: To make employees well aware of the magnetic field safety in a lab; to keep the manual in a handy place to be well prepared against emergency situations; to report an accident quickly and manage it properly when it occurs. This manual should be kept in a readily accessible place for all users who use a superconducting magnet system. In addition, education and training should be implemented to make employees fully aware of safety precautions. Since the magnetic field of a superconductive magnet is 3-dimensional, an adequate safety zone should be secured. In the assumption of all possible accidents that could take place when magnet (or magnetic field)-based medical equipment, research equipment, or portable device is used, related concepts, precautions, and response methods are systematically summarized. In addition, the sections that may be difficult to explain in written text are described using visual materials.