A common-mode filter comprises a first conductor layer, a second conductor layer, and an insulating layer placed between the first and second conductor layers. The first conductor layer has a first spiral part formed such as to draw a convolution and a first lead electrode extending from one end of the first spiral part. The second conductor layer has a second spiral part formed such as to draw a convolution and a second lead electrode extending from one end of the second spiral part. The first conductor layer is formed with third and fourth lead electrodes. The second conductor layer is formed with a connecting conductor connecting the third lead electrode to the other end of the first spiral part. The fourth lead electrode is connected to the other end of the second spiral part through a contact hole formed in the insulating layer. The third lead electrode is connected to one end of the connecting conductor through a contact hole formed in the insulating layer. The other end of the connecting conductor is connected to the other end of the first spiral part through a contact hole formed in the insulating layer.