The invention relates to a liquid-distilling device comprising : a vapour-impermeable dome (1) configured to contain in a lower part of the volume thereof the liquid to be distilled; a heat pump (2) disposed inside the dome (1) and provided with a condenser that releases heat and an evaporator that absorbs heat, respectively forming a warm part and a cool part of the heat pump; a radiator (21) connected to the warm part of the heat pump (2), suitable for evaporating the liquid to be distilled; a condenser tank (22) connected to the cool part of the heat pump (1) and suitable for condensing the evaporated liquid and collecting the distillate; and a collector tube (3) connected to the condenser tank (22) for the outlet of the distillate.