To provide a soft magnetic alloy thin film for a high frequency wave having excellent soft magnetic characteristics in a high-frequency region of 500MHz to 1GHz or more.

This invention relates to a soft magnetic alloy thin film having a ferromagnetic metal element T consisting of at least one kind of Fe, Co, Ni as a main component and being mainly composed of two phases of a crystal phase consisting of crystal grains 21 having an average crystal grain diameter not exceeding 30nm and an amorphous phase 25 existing in the grain boundary of this crystal grain 21, that is to say a soft magnetic alloy thin film 20 for a high-frequency wave in which a specific crystal orientation of crystal grains 21 is preferably oriented in the direction excepting the film surface normal direction of the soft magnetic alloy thin film.