| A planar inductor including a first substrate, a second substrate, a plurality of first strip conductors, a plurality of second strip conductors, a first planarization layer, a second planarization layer, a first magnetic layer, at least one first bonding pad and at least one second bonding pad is provided. The plurality of first strip conductors and the at least one first bonding pad are disposed on the first substrate and are electrically connected to each other. The plurality of second strip conductors and the at least one second bonding pad are disposed on the second substrate and are electrically connected to each other. The first planarization layer covers the plurality of first strip conductors. The second planarization layer covers the plurality of second strip conductors. The first magnetic layer is disposed on the first planarization layer. The at least one first bonding pad is electrically bonded to the at least one second bonding pad to electrically connect the plurality of first strip conductors and the plurality of second strip conductors. |