An image pickup apparatus performing moving-image data processing and still-image data processing in parallel includes an image pickup unit converting a ray into an electric signal and outputting an image pickup signal, a buffer unit temporarily storing the image pickup signal, a buffer controller controlling reading from the buffer unit, a first signal processing unit outputting a first transmission request, performing processing on the image pickup signal every frame timing in response to the first transmission request, and outputting moving-image data, and a second signal processing unit outputting a second transmission request, performing processing on the image pickup signal in response to the second transmission request at a predetermined timing, and outputting still-image data. The buffer controller determines whether it is possible that the image pickup signal is read without deteriorating continuity based on a data storage state of the buffer unit and the first and second transmission requests.