A foreign object detection device comprising: a set sensor coil; and a determination device that detects a foreign object, based on an electromotive force of the set sensor coil, wherein the set sensor coil includes at least one sensor coil group, the at least one sensor coil group includes, electrically connected in series: a plurality of unit sensor coils that are wound in a first winding direction; and a plurality of unit sensor coils (31, 32) that are wound in a second winding direction, the plurality of unit sensor coils that are wound in the first winding direction generate a first-sign electromotive force that causes a current to flow in a first direction in response to a change in an external magnetic field in which magnetic field distribution is uniform, the plurality of unit sensor coils (31, 32) that are wound in the second winding direction generate a second-sign electromotive force that causes a current to flow in a second direction opposite to the first direction in response to the change in the external magnetic field, each of the plurality of unit sensor coils has a coil conductor that prescribes an external shape of the unit sensor coil, and a plurality of the coil conductors included in the at least one sensor coil group are continuously and electrically connected in series, and characterized in that a part of the coil conductor which prescribes an external shape of the unit sensor coil wound in the first winding direction, prescribes an external shape of the unit sensor coil (31, 32) wound in the second winding direction. a set sensor coil; and a determination device that detects a foreign object, based on an electromotive force of the set sensor coil, wherein the set sensor coil includes at least one sensor coil group, the at least one sensor coil group includes, electrically connected in series: a plurality of unit sensor coils that are wound in a first winding direction; and a plurality of unit sensor coils (31, 32) that are wound in a second winding direction, the plurality of unit sensor coils that are wound in the first winding direction generate a first-sign electromotive force that causes a current to flow in a first direction in response to a change in an external magnetic field in which magnetic field distribution is uniform, the plurality of unit sensor coils (31, 32) that are wound in the second winding direction generate a second-sign electromotive force that causes a current to flow in a second direction opposite to the first direction in response to the change in the external magnetic field, each of the plurality of unit sensor coils has a coil conductor that prescribes an external shape of the unit sensor coil, and a plurality of the coil conductors included in the at least one sensor coil group are continuously and electrically connected in series, and characterized in that a part of the coil conductor which prescribes an external shape of the unit sensor coil wound in the first winding direction, prescribes an external shape of the unit sensor coil (31, 32) wound in the second winding direction. a plurality of unit sensor coils that are wound in a first winding direction; and a plurality of unit sensor coils (31, 32) that are wound in a second winding direction, the plurality of unit sensor coils that are wound in the first winding direction generate a first-sign electromotive force that causes a current to flow in a first direction in response to a change in an external magnetic field in which magnetic field distribution is uniform, the plurality of unit sensor coils (31, 32) that are wound in the second winding direction generate a second-sign electromotive force that causes a current to flow in a second direction opposite to the first direction in response to the change in the external magnetic field, each of the plurality of unit sensor coils has a coil conductor that prescribes an external shape of the unit sensor coil, and a plurality of the coil conductors included in the at least one sensor coil group are continuously and electrically connected in series, and characterized in that a part of the coil conductor which prescribes an external shape of the unit sensor coil wound in the first winding direction, prescribes an external shape of the unit sensor coil (31, 32) wound in the second winding direction.