Patent ID: 7619500

Claim:
A common mode filter comprising a laminate, and first, second, third, and fourth terminal electrodes formed on an outer surface of the laminate, wherein the laminate has a layered structure comprising three layers including a first coil layer, a second coil layer, and a lead layer, and insulator layers located between the three layers, wherein in the first coil layer there is a first planar coil which is formed in a substantially circular spiral shape and one end of which located outside of the spiral is electrically connected to the first terminal electrode, wherein in the second coil layer there is a second planar coil which is formed in a substantially circular spiral shape and one end of which located outside of the spiral is electrically connected to the second terminal electrode, wherein in the lead layer there are: a first lead wire one end of which is electrically connected to other end located inside of the spiral of the first planar coil and other end of which is electrically connected to the third terminal electrode; and a second lead wire one end of which is electrically connected to other end located inside of the spiral of the second planar coil and other end of which is electrically connected to the fourth terminal electrode, wherein the first lead wire has a first straight portion drawn from the inside to the outside of the spiral of the first planar coil, when viewed from a laminated direction of the laminate, wherein the second lead wire has a second straight portion drawn from the inside to the outside of the spiral of the second planar coil, when viewed from the laminated direction of the laminate, wherein the spiral of at least one of the first planar coil and the second planar coil is formed so that a plurality of first tangent lines thereto at a plurality of respective intersection points cross with the first straight portion are parallel to each other, when viewed from the laminated direction, and wherein the first straight portion is located on a straight line perpendicular to the plurality of first tangent lines, when viewed from the laminated direction.