An air pressure management device includes: a temperature conversion air pressure calculation unit that calculates a temperature conversion air pressure based on acquired temperature and air pressure of a tire; an air pressure decrease rate calculation unit that calculates an air pressure decrease rate from a change in the temperature conversion air pressure for a predetermined period, the rate indicating a declining trend of the air pressure; an air pressure decrease rate threshold value setting unit that sets an air pressure decrease rate threshold value corresponding to an acquired thermal history amount using a threshold value table, the threshold value table specifying the air pressure decrease rate threshold value associated with the thermal history amount regarding the tire; and a first determination unit that determines whether the air pressure is abnormal based on the calculated air pressure decrease rate and the set air pressure decrease rate threshold value.
