to fig3 and then upwardly into the upwardly moving charge transfer regions 13b in the present invention since each of the transfer electrodes 8a through 8e extend over the respective down and up charge transfer portions the transfer regions 13a1 13b1 and 13a2 13b2 13a3 13b3 and 13a4 and 13b4 which are adjacent each other on opposite sides of the central channel stopper region 2 they can be supplied with the same clock pulse u03c61 or u03c62 in contrast to apparatus of the prior art which must be offset from each other by one bit in the down and up transfer regions 13a and 13b respectively the length l which is in the direction of charge transfer and the width d which is transverse to the direction of charge transfer of each of the storage portions 14s of the transfer regions vary and as such regions approach the direction changing portion 5 the length l of the storage portions 14s becomes longer but the width d becomes narrower the area of the storage portions 14s remains constant by varying the dimensions d and l so that their product remains substantially constant this can be clearly observed in fig3 wherein the distance between the.