PROBLEM TO BE SOLVED: To provide liquid refrigerant piping that does not require a complicated control mechanism, and a cooling device using the same.SOLUTION: This invention provides liquid refrigerant piping that allows an evaporator to be disposed at least in a vertical direction, where the liquid refrigerant piping comprises a liquid coolant supply pipe connected to the evaporator and a liquid branch pipe connected to a side face of the liquid coolant supply pipe, and the liquid coolant supply pipe is connected so as to face obliquely upward relative to horizontal direction.