Abstract: A latent heat recovery apparatus includes a vessel having a top opening forming an exhaust port and upper and lower chambers divided by a filler layer of a porous member. Feed water is supplied and showered to the upper chamber, and exhaust gas from a gas engine is introduced into the lower chamber to heat the feed water in direct contact with the feed water thereby to produce warm water by recovering the latent heat of the exhaust gas. The warm water produced and stored in the bottom section of the latent heat recovery apparatus is supplied to a cooling water heat exchanger to reheat by cooling water of the gas engine to produce hot water to be supplied to a user.