A heat exchanger according to the present invention comprises a heat exchange portion in which heating water flow paths where heating water flows through a space between a plurality of plates, hot water flow paths through which hot water flows, and combustion gas flow paths are adjacently and alternatingly formed, wherein the heat exchange portion comprises: a heating sensible heat portion, which surrounds the outside of a combustion chamber and comprises an area on one side of the plates, for heating the heating water using the sensible heat of the combustion gas generated by combustion of the burner; a heating latent heat portion, which comprises a partial area on the other side of the plates, for heating the heating water using the latent heat of water vapors in the combustion gas which has completed heat exchanging in the heating sensible heat portion; and a hot water latent heat portion, which comprises the remaining area on the other side of the plates, for heating direct water using the latent heat of water vapors in the combustion gas which has passed through the heating latent heat portion.