A demountable current lead unit and a superconducting magnet apparatus employing the same include an inserting module that is demountably inserted into a superconducting magnet apparatus and electrode leads electrically connected to a superconducting coil and cooling pipes disposed in the respective electrode leads; a service module including a power supply source for supplying a current to the electrode leads, a refrigerant storage tank for supplying a refrigerant to the cooling pipe, and a controller for controlling a flow of the refrigerant to the cooling pipe; and a transmission pipe line for connecting the inserting module and the service module.