A multi-channel sample and hold circuit includes an operational amplifier,
plural electric charge setting channels. Each of the electric charge
setting channels includes an input terminal, an electric charge setting
capacitor, an electric charge setting switch connected between the input
terminal and the electric charge setting capacitor, a channel separating
switch connected between the electric charge setting capacitor and the
input terminal of the operational amplifier and a holding switch and a
control circuit for selecting one of the electric charge setting channels
to hold a signal that is inputted to the input terminal thereof.