Provided is a soft magnetic alloy including Fe, as a main component, and including C. the soft magnetic alloy includes an Fe composite network phase having Fe-rich grids connected in a continuous measurement range including 80000 grids, each of which size is 1 nm×1 nm×1 nm. An average of C content ratio of the Fe-poor grids having cumulative frequency of 90% or more from lower C content is 5.0 times or more to an average of C content ratio of the whole soft magnetic alloy.