A control apparatus is configured for adjusting a control value for a refrigerating machine of a cooling system and performing control of the cooling system in conformity with an environmental condition. A controller has a data base having environmental condition cells in which control values for the refrigerating machine are respectively registered in association with respective environmental conditions. The control apparatus outputs a control value suitable for the present cooling state to the refrigerating machine, registers the control value in an environmental condition cell conformed with the present environmental condition and changes the control value to construct the data base when the environmental condition varies, the controller refers to an environmental condition cell conformed with the environmental condition, corrects a control value registered at the environmental condition cell in accordance with a tendency that the control value has been changed, and outputs the corrected control value to the refrigerating machine.