The present invention is directed to an image pick-up apparatus adapted for picking up image of object, which comprises a solid-state image pick-up device (1) for performing photo-electric conversion in accordance with a received image pick-up light, a switching unit (10) for performing switching between first mode serving as image pick-up mode where charges stored in the solid-state image pick-up device (1) are read out every n (n is natural number) frames and second mode serving as image pick-up mode where charges stored in the solid-state image pick-up device (1) are read out every m (m is natural number) fields to add odd charges and even charges which are adjacent in a vertical direction of the charges which have been read out while changing the combination thereof every m fields to provide an output, and a control unit (9) for controlling the switching unit (10) in such a manner to switch the image pick-up mode into the first mode in accordance with image pick-up request at low output sensitivity, and to switch the image pick-up mode into the second mode in accordance with image pick-up request at high output sensitivity.