An active regenerative solar still with an area of 1.03 m(2), enabling one to reuse the latent heat of condensation and sensible heat of brine, is constructed and tested indoors, using a solar simulator for irradiation. In this still, a considerable fraction of the latent and sensible heat is successfully recycled and utilized for preheating the feedstock and recycling air via a falling film evaporator-condenser. The forced thin layer evaporation and film condensation, which are the efficient enhanced processes for heat transfer, are applied in this unit. As a result, the performance ratio of the unit is about two to three times greater than that of a conventional basin-type solar still (single-effect).