A linear motor comprising: a first permanent magnet row configured by arranging pairs of annular or arcuate permanent magnets to be adjacent to each other in a manner that magnetic poles of each of the pairs of the permanent magnets are rotated by at most 90 degrees to each other of the permanent magnets in a cross-section including center axes of the permanent magnets; a second permanent magnet row of annular or arcuate permanent magnets having magnetization vectors whose radial directional components are directed in the same directions as radial directional components of magnetization vectors of the corresponding radially adjacent magnets of the first permanent magnet row, and whose axial directional components are directed in directions opposite to axial directional components of magnetization vectors of the corresponding radially adjacent magnets of the first permanent magnet row; a three-phase coil provided between the first permanent magnet row and the second permanent magnet row, and formed of conductors provided outside the second permanent magnet row; a coil support means (33, 35) to which the three-phase coil is fixed, and which move the three-phase coil in parallel with a center axis of the second permanent magnet row; a magnet fixing means (13, 17) which fixes the first permanent magnet row and the second permanent magnet row to be opposed to each other in a manner that the radial directional components of the magnetization vectors of each of the rows are directed in the same directions; a coil excitation means which excites the three-phase coil and generates a predetermined thrust between the coil support means (33, 35) and the magnet fixing means (13, 17); and an electric-power transmission means which transmits an electric power output from the coil excitation means to the three-phase coil, characterized in that the first and second permanent magnet rows have substantially equal magnetization energies, and neither an iron core nor a yoke exists within main magnetic fluxes created by the first and second permanent magnet rows (11, 15) or near the three-phase coil. a first permanent magnet row configured by arranging pairs of annular or arcuate permanent magnets to be adjacent to each other in a manner that magnetic poles of each of the pairs of the permanent magnets are rotated by at most 90 degrees to each other of the permanent magnets in a cross-section including center axes of the permanent magnets; a second permanent magnet row of annular or arcuate permanent magnets having magnetization vectors whose radial directional components are directed in the same directions as radial directional components of magnetization vectors of the corresponding radially adjacent magnets of the first permanent magnet row, and whose axial directional components are directed in directions opposite to axial directional components of magnetization vectors of the corresponding radially adjacent magnets of the first permanent magnet row; a three-phase coil provided between the first permanent magnet row and the second permanent magnet row, and formed of conductors provided outside the second permanent magnet row; a coil support means (33, 35) to which the three-phase coil is fixed, and which move the three-phase coil in parallel with a center axis of the second permanent magnet row; a magnet fixing means (13, 17) which fixes the first permanent magnet row and the second permanent magnet row to be opposed to each other in a manner that the radial directional components of the magnetization vectors of each of the rows are directed in the same directions; a coil excitation means which excites the three-phase coil and generates a predetermined thrust between the coil support means (33, 35) and the magnet fixing means (13, 17); and an electric-power transmission means which transmits an electric power output from the coil excitation means to the three-phase coil, characterized in that the first and second permanent magnet rows have substantially equal magnetization energies, and neither an iron core nor a yoke exists within main magnetic fluxes created by the first and second permanent magnet rows (11, 15) or near the three-phase coil.