A seating sensor reliably senses an adult or a child seated on a vehicle seat, and prevents incorrect sensing of a seated occupant when a piece of luggage is placed on the seat. The seating sensor includes a first sensor cell, a second sensor cell connected in series with the first sensor cell and disposed on the front side of the seat beyond the first sensor cell, and a third sensor cell connected in series with the first sensor cell, connected in parallel with the second sensor cell, and disposed on the rear side of the seat beyond the first sensor cell.