In an CCD image sensor, when an image of a partial area is used, a frame rate is enhanced. Horizontal transfer of signal charges of an i-th line read out to a horizontal transfer portion is stopped at the time point when all or a part of a tail portion 74 subsequent to an extraction target portion 72. Under this state, the signal charges of an (i+1)-th line are transferred to the horizontal transfer portion. Thereafter, the horizontal transfer is started. Through this operation, unnecessary signal charges of the tail portion 74 of the i-th line and unnecessary signal charges of a head portion 82 of an (i+1)-th line are combined. By partially overlapping adjacent lines with each other, the cycle number of horizontal transfer clocks required for the horizontal transfer per line can be reduced as compared with a normal operation, thereby enhancing a frame rate.