The spherical desalination device includes a hollow spherical transparent shell serving as a distillation chamber or still. Water initially flows through an underground system for geothermal heating, then flows into the hollow shell. The water flows from the upper portion of the shell, filling a series of concentric circular trays arranged in a conical stack within the shell. Water cascades from the smallest diameter uppermost tray to the largest lowermost tray, in sequence. Sunlight focused on the transparent shell causes the water to evaporate, and condensation collects upon the interior surface of the shell. A resilient seal extends about the lower rim of the largest and lowest evaporator tray, and is located at the equator of the hollow shell. The shell is rotated by an external motor, thereby drawing the internal surface of the shell across the seal to remove collected condensation from the internal surface of the shell.