A vehicular air conditioning system includes an air-conditioning case having a plurality of passages divided by a partition wall, and an ion generator configured to emit anions and cations into the passages. The ion generator includes a plurality of discharge electrodes installed to extend into the passages of the air-conditioning case and configured to emit anions and cations into the passages. The partition wall of the air-conditioning case includes a communication portion configured to bring the passages into communication with each other so that the discharge electrodes installed in the passages face each other in the same space.