To solve such the problem that the conventional oxygen concentration apparatus with a magnet set in a tube can not effectively take in oxygen in the air and it is difficult to easily and inexpensively concentrate oxygen in volume.

Either one of a rotating magnetic field device 3 comprising an electromagnet 18 using a three-phase AC coil 14 or the like and a rotating magnetic field device 3 which comprises a permanent magnet 4, a rotary shaft 8 and a motor 11, in which a rotary shaft 9 is disposed between the N pole 5 and the S pole 6 of the permanent magnet 4, and which has the motor 11 for rotating the rotary shaft 9, is disposed in the vicinity of one end of a nonmagnetic gas passage 17. It is preferable that a fan 10 is provided to the nonmagnetic gas passage 17. It is more preferable that the nonmagnetic gas passage 17 is a nonmagnetic pipe 9 or the like.