A desalination system, etc. of the present disclosure includes: a water tank; a water-repellent particle layer that is located below the water tank and contains a plurality of water-repellent particles; a liquefying layer that is located below the water-repellent particle layer and liquefies water vapor that has passed through the water-repellent particle layer, to obtain fresh water; an introduction channel of a liquid supply channel that supplies a liquid to the water tank; and a liquid speed reduction part that is located on the introduction channel of the supply channel, and includes a wall surface crossing a flow direction of the liquid in the supply channel, for reducing a flow speed of the liquid.