PURPOSE: To satisfactorily image-pick up a document and an illustration image with high resolution.

CONSTITUTION: When a selection means 207 selects a second mode for image- picking up a sentence and the like, an image pickup signal exposed in an exposure means 202 is added to a second mode means 206 through a gain control means 203, a clamping means 204 and the selection means 207, and a high resolution image signal is generated. On the other hand, the image pickup signal is level-detected in a detection means 208. A control means 209 executes both exposure quantity control by the exposure means 202 or gain control by the gain control means 203 or either of them in accordance with a peak level among the detection levels. At that time, a correction means 209a sets the target value of the level of the image pickup signal in accordance with the mode, and executes control so that the detection level becomes the target value. Thus, the satifactory image can be obtained in spite of the character density of the sentence.