An image processing apparatus comprising: a motion vector calculator configured to calculate motion vector information between a fluorescence image of an observed region based on fluorescence generated from the observed region irradiated with excitation light, and a reflected-light image of the observed region based on reflected light from the observed region irradiated with white light, wherein the motion vector calculator is configured to calculate motion vector information between a reflected-excitation-light image based on the excitation light reflected from the observed region, and the reflected-light image as the motion vector information between the fluorescence image and the reflected-light image; and an alignment processing unit configured to correct misalignment of an object between the fluorescence image and the reflected-light image based on the motion vector information; characterized in that the image processing apparatus further comprises: a reflected-light image storage unit which is configured to acquire the image information of the reflected-excitation-light image from a reflected-light imaging unit capturing the reflected-excitation-light image at a time when the observed region is irradiated with the excitation light, and to acquire the image information of the reflected-light image from the reflected-light imaging unit capturing the reflected-light image at a time when the observed region is irradiated with the white light; and a fluorescence image storage unit which is configured to acquire the image information of the fluorescence image from a fluorescence imaging unit capturing the fluorescence image at the time when the observed region is irradiated with the excitation light. a motion vector calculator configured to calculate motion vector information between a fluorescence image of an observed region based on fluorescence generated from the observed region irradiated with excitation light, and a reflected-light image of the observed region based on reflected light from the observed region irradiated with white light, wherein the motion vector calculator is configured to calculate motion vector information between a reflected-excitation-light image based on the excitation light reflected from the observed region, and the reflected-light image as the motion vector information between the fluorescence image and the reflected-light image; and an alignment processing unit configured to correct misalignment of an object between the fluorescence image and the reflected-light image based on the motion vector information; characterized in that the image processing apparatus further comprises: a reflected-light image storage unit which is configured to acquire the image information of the reflected-excitation-light image from a reflected-light imaging unit capturing the reflected-excitation-light image at a time when the observed region is irradiated with the excitation light, and to acquire the image information of the reflected-light image from the reflected-light imaging unit capturing the reflected-light image at a time when the observed region is irradiated with the white light; and a fluorescence image storage unit which is configured to acquire the image information of the fluorescence image from a fluorescence imaging unit capturing the fluorescence image at the time when the observed region is irradiated with the excitation light. a reflected-light image storage unit which is configured to acquire the image information of the reflected-excitation-light image from a reflected-light imaging unit capturing the reflected-excitation-light image at a time when the observed region is irradiated with the excitation light, and to acquire the image information of the reflected-light image from the reflected-light imaging unit capturing the reflected-light image at a time when the observed region is irradiated with the white light; and a fluorescence image storage unit which is configured to acquire the image information of the fluorescence image from a fluorescence imaging unit capturing the fluorescence image at the time when the observed region is irradiated with the excitation light.