Granular substance, magnetic thin film, and magnetic device

A granular substance (1) having soft magnetic properties is provided which contains a matrix (3) composed of a nonmagnetic insulating organic material and ferromagnetic metal particles (2) dispersed in the matrix (3) and having a mean particle size of 50 nm or less, wherein the volume ratio of the matrix (3) is in the range of 5 to 50%. When the granular substance (1) is in the form of a film, it has a complex permeability the real part ( mu ') of which is 40 or more at 1 GHz, a quality factor Q (Q = mu '/ mu " where mu " is the imaginary part of the complex permeability) of 1 or more, and a saturation magnetization of 5 kG or more.