PURPOSE: To obtain an air pump having a long life without noise by a construction wherein at least two chambers are driven by one drive unit so as to obtain sufficient cooling power by letting air currents flow one after the other.

CONSTITUTION: A pump body 10 having two chambers 11, 12 which are mutually the same form sound resonance, and the inside of the chambers 11, 12 is divided by a partition 13 in which a hole 15 is made for fitting an oscillating plate 14 as a drive unit. The oscillating plate 14 is fitted in the hole 15, and the chambers 11, 12 are made independent mutually. If the oscillating plate 14 is oscillated, a phase falls in such a state that it lags by 180 degrees, and air currents sent out of ports 11a, 12a flow one after the other. When the resonant frequencies of the chambers 11, 12 are the same, cooling efficiency is the most excellent. In case the resonant frequencies are different, two materials to be cooled can be cooled separately at a different time.