This chapter deals with utilities used in a biochemical process industry such as, air, water, steam, coolant and other auxiliary process such as, sterilization. Air is required in aerobic fermentor. Water is used in the process as well as a cooling the liquid in reactors, condensers and crystallizers. Coolant is required for condensing gases or cooling the contents of a liquid. Steam finds application in distillation columns, evaporators, etc., for heating the contents. Usage of utilities determines the product variable cost or product operating cost. Higher is this value, higher will be the product variable cost. Hence, minimum usage of utilities is always desired.