An image processing device for an endoscope, comprising: a candidate abnormal region determining unit (110, 210) that calculates a color feature data by using pixel values of an intra-luminal image captured by the endoscope and determines a candidate abnormal region from the intra-luminal image by comparing the calculated color feature data with a first determination criterion; a bubble region determining unit (120, 220) that determines a bubble region from the intra-luminal image, wherein the bubble region is a region on which a bubble is captured in the intra-luminal image; a bubble inside determining unit (130, 230, 310) that determines whether the candidate abnormal region is present inside the bubble region based on a determination result of the bubble region; and an abnormal region determining unit (140, 240, 320) that determines whether the candidate abnormal region is an abnormal region using the calculated color feature data and a second determination criterion different from the first determination criterion when the candidate abnormal region is determined to be present inside the bubble region, wherein the bubble region determining unit (120, 220) includes a peripheral region determining unit (121, 221) that determines a region which has the features of a peripheral region of the bubble region, and the peripheral region determining unit (121, 221) includes an arc-shaped region determining unit (121a, 221a) that determines an arc-shaped region from the intra-luminal image, the bubble region determining unit includes an inner region determining unit that determines a region which has the features of an inner region of the bubble region, and the inner region determining unit includes a halation region determining unit that determines a halation region from the intra-luminal image, the bubble region determining unit (120, 220) sets the determined arc-shaped region and the determined halation region as the bubble region, portions in the intra-luminal image that are determined to be abnormal region by satisfying the second determination criterion are fewer than portions in the intra-luminal image that are determined to be the candidate abnormal region by satisfying the first determination criterion, and the abnormal region determining unit includes a determination criterion creating unit that adaptively creates the second determination criterion based on color feature data of a surrounding region of the candidate abnormal region. a candidate abnormal region determining unit (110, 210) that calculates a color feature data by using pixel values of an intra-luminal image captured by the endoscope and determines a candidate abnormal region from the intra-luminal image by comparing the calculated color feature data with a first determination criterion; a bubble region determining unit (120, 220) that determines a bubble region from the intra-luminal image, wherein the bubble region is a region on which a bubble is captured in the intra-luminal image; a bubble inside determining unit (130, 230, 310) that determines whether the candidate abnormal region is present inside the bubble region based on a determination result of the bubble region; and an abnormal region determining unit (140, 240, 320) that determines whether the candidate abnormal region is an abnormal region using the calculated color feature data and a second determination criterion different from the first determination criterion when the candidate abnormal region is determined to be present inside the bubble region, wherein the bubble region determining unit (120, 220) includes a peripheral region determining unit (121, 221) that determines a region which has the features of a peripheral region of the bubble region, and the peripheral region determining unit (121, 221) includes an arc-shaped region determining unit (121a, 221a) that determines an arc-shaped region from the intra-luminal image, the bubble region determining unit includes an inner region determining unit that determines a region which has the features of an inner region of the bubble region, and the inner region determining unit includes a halation region determining unit that determines a halation region from the intra-luminal image, the bubble region determining unit (120, 220) sets the determined arc-shaped region and the determined halation region as the bubble region, portions in the intra-luminal image that are determined to be abnormal region by satisfying the second determination criterion are fewer than portions in the intra-luminal image that are determined to be the candidate abnormal region by satisfying the first determination criterion, and the abnormal region determining unit includes a determination criterion creating unit that adaptively creates the second determination criterion based on color feature data of a surrounding region of the candidate abnormal region.