PURPOSE: To decrease the operating quantity of an operator and to shorten a cumulative access time by arranging the stored card of design data, sweeping the card and storing the read data to a memory.

CONSTITUTION: Since the design data of one element to constitute a circuit are coded and inputted respective magnetic cards 8aW8c, a designer uses the necessary number of a magnetic cards and constitutes the circuit on a flat plate 9. When the work is completed and a reading instruction is added through a key terminal 6 to a CPU 4, the CPU 4 generates the signal to start a reading part 12 and a motor 13 for driving through an interface part 5. Since the rotation of the motor 13 is propagated to a belt 14, the reading part 12 shifts along the flat plate 9, and thus, while the reading part 12 shifts, the position data of the card and the data stored in the card are read as design data. The signal is inputted through the interface part 5 and the CPU 4 to a memory 3. The input of the circuit element can be executed by these actions.