To provide a freezing device, a frozen ground calculation system, a freezing method, etc. for shortening the frozen ground formation period by knowing the minimum time of frozen ground formation required for placing the frozen ground in service, and for reducing a frost heaving phenomenon and a freeze expansion pressure caused by excessive growth of the frozen ground by controlling the brine temperature.

When the frozen ground maximum stress falls below the frozen ground intensity, the optimum frozen ground temperature is calculated by an optimum frozen ground temperature calculating means 63, and the optimum brine temperature is calculated by an optimum brine temperature calculating means 65.