A split type magnet device for a high-sensitivity NMR apparatus to be used for solution analysis generates a remarkably uniform magnetic field at the center portion of the magnet device used for determining a sample. The magnet device for NMR apparatus has first multilayer coils and second multilayer coils, which face each other with a predetermined distance being provided therebetween, each of pairs of the first and the second coils being substantially coaxial with respect to a central axis, and each of layers of each of the first and the second multilayer coils having at least one coil. An energizing current of at least one of the coils constituting an innermost layer of each of the first and the second multilayer coils is in a minus direction, when an energizing current of the coil used for generating a main magnetic field for NMR detection in the vicinity of a center portion of the apparatus is in a plus direction.