High efficiency waste heat recovery device of hot air oven

The present invention relates to a high efficiency waste heat recovery device for a hot air oven, which comprises: a main body including a waste gas inlet formed at one lower side to allow waste gas to flow into the inside thereof, an outside air inlet formed at the other lower side to allow the outside air to flow into the inside thereof, an outside air outlet formed at one upper side to discharge the outside air introduced into the inside through the outside air inlet, and a waste gas outlet formed at the other upper side to discharge the waste gas introduced into the inside through the waste gas inlet; upper and lower diaphragms installed to partition diagonally inside the main body and spaced apart by a predetermined distance to form a partitioned space of a predetermined size along the outside air inlet and the outside air outlet; and a plurality of fin tubes installed in a plurality of rows to cross in a spaced space between the upper and lower diaphragms and having a plurality of independent flow paths