A soft magnetic alloy film includes: a fine crystalline phase having an average grain size of 10 nm or less and essentially consisting of Fe of b-c-c structure; and an amorphous phase containing a rare earth element or at least one of the elements, Ti, Zr, Hf, V, Nb, Ta and W, and O (oxygen) in a large amount, the fine crystalline phase and amorphous phase existing in a mixed state, with the proportion of the fine crystalline phase of Fe of b-c-c structure to the entire structure being 50% or less. A plane magnetic element employs such a soft magnetic alloy.