PURPOSE: To obtain a simple and small sized serial/parallel conversion circuit suitable for circuit integration and possible for high speed operation by changing a shift direction and an output signal extraction latch circuit for each frame so as to apply serial/parallel mutual conversion one after another.

CONSTITUTION: Storage elements 11-14, 21-24, 31-34, 41-44 comprising of total 16 sets of flip-flop circuits of 4-row and 4-column in longitudinal and lateral directions are arranged and a common selection command signal is given to 2-1 selector circuits 51-55, 61-65, 71-75, 81-85 from a timing control circuit 9. The circuit components are repetitively arranged longitudinally and laterally and serial/parallel mutual conversion is applied by switching the selection of the selector circuits for each frame. Thus, a simple and small sized serial/ parallel mutual conversion circuit suitable for an integrated circuit and in response to high speed processing easily is attained.