An image processing device comprising: nucleus-candidate-region extracting means for extracting, from a captured image obtained by image-capturing a sample piece including a target cell having a nucleus, a nucleus candidate region corresponding to the nucleus by extracting pixel blocks of pixels with intensity values being equal to or larger than a threshold from a captured image; a determination-subject-region setting unit for setting a rectangular region centered at each single pixel of the pixels included in each nucleus candidate region as a determination subject region; an image-feature extracting unit for extracting, for each determination subject region, an image feature amount of an image of the determination subject region; a reliability calculating unit for acquiring, for each determination subject region, a numerical value indicating reliability that an image in the determination subject region is an image of a target cell on the basis of a feature amount of the image of the determination subject region; a target-cell-candidate-region setting unit for setting a target cell candidate region, wherein the target-cell-candidate-region setting unit sets each determination subject region with reliability being a threshold or higher as a target cell candidate region; a display-subject-region setting unit for setting a display subject region corresponding to a nucleus candidate region, on the basis of plural target cell candidate regions that at least partly overlap the nucleus candidate region, wherein the display-subject-region setting unit calculates on the basis of reliabilities of plural target cell candidate regions that at least partly overlap a nucleus candidate region, integrated reliability of the display subject region; and a display-subject-region displaying unit for cutting out images in the respective display subject regions from the captured image, and causing the display to display a list of the images of the respective display subject regions. nucleus-candidate-region extracting means for extracting, from a captured image obtained by image-capturing a sample piece including a target cell having a nucleus, a nucleus candidate region corresponding to the nucleus by extracting pixel blocks of pixels with intensity values being equal to or larger than a threshold from a captured image; a determination-subject-region setting unit for setting a rectangular region centered at each single pixel of the pixels included in each nucleus candidate region as a determination subject region; an image-feature extracting unit for extracting, for each determination subject region, an image feature amount of an image of the determination subject region; a reliability calculating unit for acquiring, for each determination subject region, a numerical value indicating reliability that an image in the determination subject region is an image of a target cell on the basis of a feature amount of the image of the determination subject region; a target-cell-candidate-region setting unit for setting a target cell candidate region, wherein the target-cell-candidate-region setting unit sets each determination subject region with reliability being a threshold or higher as a target cell candidate region; a display-subject-region setting unit for setting a display subject region corresponding to a nucleus candidate region, on the basis of plural target cell candidate regions that at least partly overlap the nucleus candidate region, wherein the display-subject-region setting unit calculates on the basis of reliabilities of plural target cell candidate regions that at least partly overlap a nucleus candidate region, integrated reliability of the display subject region; and a display-subject-region displaying unit for cutting out images in the respective display subject regions from the captured image, and causing the display to display a list of the images of the respective display subject regions.