An image signal correcting device (15) has at least a color mixing corrector (151) that receives an image signal arising from photoelectric conversion by a color imaging element (12), and corrects a color mixing component included in this image signal, and a storage unit (153) that stores a color mixing correction coefficient set in advance for each of a plurality of areas segmented in matching with the imaging plane of the imaging element (12). The color mixing corrector (151) approximates the color mixing correction coefficient read out from the storage unit (153) by interpolation to acquire a color mixing rate at the necessary pixel position in color mixing correction, and corrects the color mixing component by using the acquired color mixing rate.