The invention relates to a portable, solar-thermal device for the treatment of drinking water from waste water, comprising an evaporation container that accommodates the waste water, a condensation apparatus having a flow connection to the evaporation container, and a separator arranged between the evaporation container and the condensation apparatus for separating and leading away the condensate obtained in the condensation apparatus. According to the invention, the separator has passage openings for the transfer of water vapor into the condensation apparatus, which is arranged on the top side of the device in the operating position of the device, and a drain opening for the condensate arising in the condensation apparatus, which drain opening can be connected to a collecting container, wherein the evaporation container, which is arranged on the bottom side of the separator, is designed as a flexible film bag.