A transformer includes a first coil spiraling inwardly in a second direction. A second coil spirals along the first coil on the outside relative to the first coil. First and second external electrodes are provided in third and fourth directions relative to a first line passing through a gravity center of the first coil and an outer end thereof, respectively, the third direction being perpendicular to the first line, and the fourth direction being opposite thereto. First and second lead-out conductors are connected to the outer end of the first and the second coil, respectively, and electrically connected to the first and the second external electrodes, respectively. Both coils spiral along each other throughout their lengths. By spiraling in the second direction, the first coil is, at the outer end, oriented in a fourth direction.