A feeding device includes: a supply unit that supplies air into space between plural media loaded to float the media; a feeder that adsorbs the media floated by the supply unit and feeds the media; a separator that supplies air to a second medium disposed immediately below a first medium adsorbed by the feeder to separate the second medium from the first medium; a detector that detects a position of at least one of the first medium and the second medium after air is supplied by the separator; and a modifier that modifies a condition related to a feeding operation of the feeder based a position detected by the detector.