Disclosed is an ice bank for a refrigerator including: an inner case and an outer case forming one storage space having an opened top by being coupled to each other; and a coupling unit coupling the inner and outer cases to each other so that either one is relatively movable with respect to the other one so as for the capacity of the storage space to be variable. The apparatus incorporates a capacitor for providing a signal path for a high frequency signal from a first potential to a second potential. Address electrodes are formed on the second substrate. An unanswered communication to the group identifier is received on all the communication devices in the group. A conductive terminal such as a bump is formed on the second wiring. The preparation of esters of fatty acids with polyols that contain lactic acid is also described.