A magnetic element includes a first magnetic core, a second magnetic core, a first winding and a second winding. The first magnetic core includes a first lateral core part, a second lateral core part and a first middle core part between the first lateral core part and the second lateral core part. The second magnetic core includes a third lateral core part, a fourth lateral core part and a second middle core part between the third lateral core part and the fourth lateral core part. The third lateral core part is located beside the first middle core part. The second middle core part is located beside the second lateral core part. The first winding is wound around the first middle core part and the third lateral core part. The second winding is wound around the second middle core part and the second lateral core part.