A moving magnetic field generating apparatus, characterized by comprising: a magnet array including a plurality of magnets disposed at a first pitch (rp) such that N and S poles of adjacent magnets in the magnet array are alternated; and first and second magnetic pole piece arrays (7,9) extending along the magnet array to interpose the magnet array therebetween with a gap from the magnet array, the first and second magnetic pole piece arrays (7,9) being disposed with a predetermined phase difference between each other, the first magnetic pole piece array including a plurality of first magnetic pole pieces disposed at a second pitch (τs) in an array and each having a length enough to face at least two adjacent magnets in the magnet array, the second magnetic pole piece array including a plurality of second magnetic pole pieces disposed at the second pitch (τs) in an array and each having a length enough to face at least two adjacent magnets in the magnet array, the first and second pitches (τp,τs) and the phase difference are determined such that, when one of the first and second magnetic pole piece arrays (7, 9) and the magnet array makes a relative movement with respect to the other at a predetermined relative moving speed, magnetic flux emanating from n consecutive magnets in the magnet array, where n is a natural number, forms synthesized magnetic flux that sequentially passes through the first magnetic pole pieces in the first magnetic pole piece array facing the n magnets and the second magnetic pole pieces in the second magnetic pole piece array facing the n magnets, thereby forming moving synthesized magnetic poles and forming a high-speed moving magnetic field in which the synthesized magnetic poles move at a speed faster than the predetermined relative moving speed. a magnet array including a plurality of magnets disposed at a first pitch (rp) such that N and S poles of adjacent magnets in the magnet array are alternated; and first and second magnetic pole piece arrays (7,9) extending along the magnet array to interpose the magnet array therebetween with a gap from the magnet array, the first and second magnetic pole piece arrays (7,9) being disposed with a predetermined phase difference between each other, the first magnetic pole piece array including a plurality of first magnetic pole pieces disposed at a second pitch (τs) in an array and each having a length enough to face at least two adjacent magnets in the magnet array, the second magnetic pole piece array including a plurality of second magnetic pole pieces disposed at the second pitch (τs) in an array and each having a length enough to face at least two adjacent magnets in the magnet array, the first and second pitches (τp,τs) and the phase difference are determined such that, when one of the first and second magnetic pole piece arrays (7, 9) and the magnet array makes a relative movement with respect to the other at a predetermined relative moving speed, magnetic flux emanating from n consecutive magnets in the magnet array, where n is a natural number, forms synthesized magnetic flux that sequentially passes through the first magnetic pole pieces in the first magnetic pole piece array facing the n magnets and the second magnetic pole pieces in the second magnetic pole piece array facing the n magnets, thereby forming moving synthesized magnetic poles and forming a high-speed moving magnetic field in which the synthesized magnetic poles move at a speed faster than the predetermined relative moving speed.