An electronic device including a core, at least a wire and a magnetic material is provided. The core includes a pillar, a top board and a bottom board. The pillar is disposed between the top board and the bottom board. A winding space is formed among the top board, the bottom board and the pillar. The wire is wound around the pillar and located in the winding space. The magnetic material fills the winding space to encapsulate the wire. The magnetic material includes a resin and a magnetic powder, wherein an average particle diameter of the magnetic powder is smaller than 20 μm.