A heat exchanger comprising: a heat exchange unit in which heating medium flow channels through which a heating medium flows in a space between a plurality of plates and combustion gas flow channels through which a combustion gas combusted in a burner flows are alternately formed to be adjacent to each other, wherein the heat exchange unit is configured with a sensible heat unit configured to surround an outer side of a combustion chamber, configured with a region at one side of each one of the plates and configured to heat the heating medium using sensible heat of the combustion gas generated by combustion of the burner; and a latent heat unit configured with a region at the other side of each one of the plates and configured to heat the heating medium using latent heat of water vapor contained in the combustion gas which undergoes heat exchange in the sensible heat unit; and characterised in that the plurality of plates are formed by stacking a plurality of unit plates each having a first plate and a second plate which are stacked, wherein the heating medium flow channel is formed between the first plate and the second plate of the unit plate, and the combustion gas flow channel is formed between a second plate constituting a unit plate disposed at one side of adjacent stacked unit plates and a first plate of a unit plate disposed at the other side thereof, the sensible heat unit is configured with a region at one side of the first plate and the second plate which are stacked, and the latent heat unit is configured with a region at the other side of the first plate and the second plate which are stacked, a plurality of first guide units and a plurality of second guide units configured to guide the heating medium to flow near to a center of the combustion chamber are formed at a heating medium flow channel of the sensible heat unit and formed and circumferentially spaced apart at an outer side portion of the sensible heat unit wherein the plurality of first guide units protrudes from the first plate toward the heating medium flow channel, and the plurality of second guide units protrudes from the second plate toward the heating medium flow channel and is formed at positions corresponding to the plurality of first guide units. a heat exchange unit in which heating medium flow channels through which a heating medium flows in a space between a plurality of plates and combustion gas flow channels through which a combustion gas combusted in a burner flows are alternately formed to be adjacent to each other, wherein the heat exchange unit is configured with a sensible heat unit configured to surround an outer side of a combustion chamber, configured with a region at one side of each one of the plates and configured to heat the heating medium using sensible heat of the combustion gas generated by combustion of the burner; and a latent heat unit configured with a region at the other side of each one of the plates and configured to heat the heating medium using latent heat of water vapor contained in the combustion gas which undergoes heat exchange in the sensible heat unit; and characterised in that the plurality of plates are formed by stacking a plurality of unit plates each having a first plate and a second plate which are stacked, wherein the heating medium flow channel is formed between the first plate and the second plate of the unit plate, and the combustion gas flow channel is formed between a second plate constituting a unit plate disposed at one side of adjacent stacked unit plates and a first plate of a unit plate disposed at the other side thereof, the sensible heat unit is configured with a region at one side of the first plate and the second plate which are stacked, and the latent heat unit is configured with a region at the other side of the first plate and the second plate which are stacked, a plurality of first guide units and a plurality of second guide units configured to guide the heating medium to flow near to a center of the combustion chamber are formed at a heating medium flow channel of the sensible heat unit and formed and circumferentially spaced apart at an outer side portion of the sensible heat unit wherein the plurality of first guide units protrudes from the first plate toward the heating medium flow channel, and the plurality of second guide units protrudes from the second plate toward the heating medium flow channel and is formed at positions corresponding to the plurality of first guide units.