An electronic zoom apparatus is used in an image pickup device constructing one frame while a raster scanning is performed with respect to image data of first and second fields. The apparatus comprises a memory for storing first image data of the first field and second image data of the second field; a frame making circuit for transmitting a control signal to the memory in accordance with a control signal transmitted from a control section such that the stored first and second image data are synthesized as one frame and are read at random; and an interpolating circuit for performing an interpolation processing with respect to the first and second image data transmitted from the memory by the control signal transmitted from the frame making circuit. Further, the apparatus may comprise an interpolating circuit control section for detecting the difference between adjacent first and second image data transmitted from the memory and controlling the interpolating circuit to be turned on and off by the detecting result. The interpolating circuit comprises a memory device for supplying the image data to be interpolated as an address signal and reading the image data stored to an address indicated by this address signal and interpolation-processed in advance by the image data. The data read out of the memory device are set to interpolating data.