PURPOSE: To perform data retrieval easily and at a high speed by storing data in a memory circuit through sorting function circuit.

CONSTITUTION: A data string, inputted from input terminal 8, is supplied to sorting function circuit 3 through buffer circuit 4. The data sorted in fixed order by sorting function circuit 3 is stored in memory circuit 1 according addresses by operating address selector circuit 2 on the basis of the control information of control circuit 6. In this way, data from sorting function circuit 3 are arrayed on memory circuit 1 being sorted. Therefore, when data to be retrieved are inputted to terminal 10, data equal to the key of retrieved data are selected from memory circuit 1 and outputted, thereby making it possible to retrieve data easily and rapidly.