. . "FIG. 11A is a plan view showing an eleventh embodiment of the solid state image pick-up element according to the invention, and FIG. 11B is a cross sectional view cut along line X-X' of the embodiment shown in FIG. 11B. In this embodiment, the solid state image pick-up element 81 has an IGLT construction in which the source region and the drain region are formed concentrically with each other and" . .