A solid-state image pickup device according to one aspect of the present invention includes, but is not limited to: first and second substrates on which circuit elements constituting a pixel; a coupler electrically coupling the first and second substrates; a first photoelectric conversion element on the first substrate; a first amplifier circuit on the first substrate; a first storing unit on the second substrate; and an output circuit on the second substrate. The first photoelectric conversion element performs photoelectric conversion on a first incident light to generate a first signal. The first amplifier circuit is coupled in series to the first photoelectric conversion element. The first amplifier circuit amplifies the first signal to generate a first amplified signal and output the first amplified signal to the coupler. The first storing unit stores the first amplified signal. The output circuit sequentially outputs the first amplified signal stored.