Abstract: An ion-exchange membrane has a mesh structure with microscopic pores in which water can infiltrate. When the ion-exchange membrane is incorporated in the sensor body, the one side of the membrane comes in contact with the sample solution and the other side thereof comes in contact with the internal solution. The water in the internal solution gradually migrates to the side of the sample flow path permeating through the membrane. When the sensor is used for extended periods of time, therefore, the sensor performance often decreases due to a decrease in the electric conductivity between the internal electrode and the ion-exchange membrane.

Abstract: The object of the present invention is to provide a multichip IC card which seems to be a single chip IC card constituted by one chip and in which plural function chips are built. The multichip IC card is provided with a connector 3 for connecting to an interface processor 1, a master chip 4 for controlling a system in a card, at least one function chip 6-1 to 6-n and selection means 5A for connecting the function chip selected by the master chip and the interface processor 1 via the connector 3.