The utility model provides a heat exchanging device which contains a casing, a heat exchanging module and a piezoelectricity module. Be formed with an inner loop room and an extrinsic cycle room of mutual isolation in the casing. Heat exchanging module sets up in the casing, and heat exchanging module includes the one on top of another and mutual a plurality of slabs that separate the configuration, the both sides of one of them slab respectively with another adjacent slab enclose establish into intercommunication inner loop room one in an outer runner of runner and intercommunication extrinsic cycle room. Piezoelectricity module setting is in the casing, and the piezoelectricity module includes a piezoelectricity wafer, and the piezoelectricity module has the respectively first heat exchange side and a second heat exchange side of hot link piezoelectricity wafer, and first heat exchange side position is in the inner loop is indoor and second heat exchange side position is indoor in the extrinsic cycle, the piezoelectricity wafer borrow this and can including carry heat energy between circular chamber and the extrinsic cycle room. The utility model discloses a heat exchanging device need not increase the slab size can obtain the heat -sinking capability stronger than prior art.