Disclosed herein is a common mode filter, including: first and second coil layers electromagnetically coupled to each other; a pair of external terminals connected to ends of the first coil layer and a pair of external terminals connected to ends of the second coil layer; a first ESD prevention member connecting between the pair of external terminals carrying electric current with the first coil layer and a second ESD prevention member connecting between the pair of external terminals carrying electric current with the second coil layer; and a ground electrode connecting the first ESD prevention member to the second ESD prevention member, wherein the ground electrode has a stepped portion formed at the center.