To contrive weight and cost reduction by reducing the volume of a magnet.

For this electromagnetic driver, all of the moving member are magnetized in the same direction in the case that the moving material 1 includes one or more magnetized parts 2, and the material of the magnetized part has actually linear demagnetization up to 100°C at least and to the negative value of the density of magnetic fluxes where at least the absolute value is roughly equal to half the remanence of the above material, and the magnetic circuit part 5 and the magnetized part are adjusted so that the average working point of each of the magnetized parts may come to the value of the density of magnetic fluxes smaller than half the value of the remanence of the magnetic material in the case that currents are not flowing to coils 12 and 13.