To provide a dark current noise removing device having a reduced memory capacity for an image-pickup element.

A dark current noise component the image of which is picked up with a shutter 16 closed is compressed and stored in a memory 4, and subtracted by a subtracting circuit 5 from a normally picked up and compressed image signal to remove dark current noise. Thus, the dark current noise component is compressed to decrease the amount of information as compared with that before compression, thereby enabling reduction in the capacity of the memory 4 for information storage.