An electronic endoscope apparatus includes an imaging element and a signal processing unit. The imaging element obtains an image of an observation object, and outputs an image signal of the observation object. The signal processing unit alternately repeats obtainment of a partial image signal using a part of a light receiving area of the imaging element and obtainment of a partial image signal using the remaining part of the light receiving area. The signal processing unit also obtains a whole image signal corresponding to an image of the observation object using a partial image signal obtained in the n-th (n is a natural number) obtainment and a partial image signal obtained in the (n+1)th obtainment. Further, a partial component of the n-th partial image signal is extracted by an extraction unit, and the extracted partial component is added to the (n+1)th partial image signal.