A magnetic element includes a first magnetic core, a second magnetic core and a plurality of conducting wires. The first magnetic core includes a first coiling body, a first protruding portion and a second protruding portion. The second magnetic core includes a second coiling body, a third protruding portion and a fourth protruding portion. A soldering surface of the first protruding portion is parallel and next to a soldering surface of the fourth soldering surface. Since an extension direction of the first magnetic core is extended from the soldering surface of the first protruding portion, an extension direction of the second magnetic core is extended from the soldering surface of the second protruding portion, and the plurality of conducting wires can be coiled on the first and the second coiling bodies respectively, the transformer can provide more space for coiling than the prior art.