The present invention provides a cold water tank. In the cold water tank, an accommodation space for accommodating a fluid is partitioned by means of partition walls alternately disposed in the transverse direction such that the fluid flows straight along the partition walls, and an evaporator having m evaporation pipes forming an offset and m-1 connection pipes connecting the m evaporation pipes is disposed in the accommodation space opposite to the partition walls so as to be heat-exchanged with the fluid. Therefore, the cold water tank has increased contact surface area heat-exchanged with the fluid and prevents excessive ice formation, and thus provides an enhanced cold water dispensing performance.