A magnetic element and a power supply which can output a plurality of different output pulse signal voltages or different output AC voltages while preventing an increase in the number of parts or an area occupied by parts are provided. The magnetic element includes a magnetic core which includes an inner leg portion, a first outer leg portion and a second outer leg portion (hereinafter referred to as the outer leg portions) which share the inner leg portion, and each of which forms a loop magnetic path together with the inner leg portion. An inner leg coil is wound around the inner leg portion, and an outer leg coil is wound around the outer leg portions. The outer leg coil is wound around the outer leg portions so that magnetic fluxes generated in the outer leg portions by a current flowing through the outer leg coil cancel each other out in the inner leg portion.