To provide a compact and energy-saving apparatus using a coulomb force, wherein the apparatus requires conventionally a large installation and a high power, nonmatching to an energy-saving time as the apparatus generates a static electricity by spraying air on a seat and causes the seat to be charged even if a foreign substance can be removed according to circumstances, resulting in attracting the foreign substance in a following step.

The apparatus has an air nozzle 2, an ionizer 3, a brush 6 for causing a conductor 5 to be charged in contact in a polarity opposite to the foreign substance while the foreign substance 9 blew off from the seat 1 is charged to keep a plurality of conductors 5 separated and arranged on a rotatable and nonconductive role 4, and a blade 7 of the conductor carrying an earth function, wherein the foreign substance scraped down from the conductor is dust collected together with air as a solid-gas mixture.