The objective of this study was to identify former municipalities that are not depopulated but have a population decrease equivalent to that of depopulated areas by analyzing the population of each former municipality, and to position them as "forgotten depopulated areas". Specifically, geospatial data was manipulated in GIS to calculate the population requirement indices based on the current depopulation law for each former municipality, and former municipalities that met the criteria for depopulated areas but were classified as non-populated areas were identified as "forgotten depopulated areas. As a result, approximately 10% of all former municipalities in the target area were identified as "forgotten depopulated areas," indicating the universal existence of "forgotten depopulated areas," at least in the target area of this study. Since "forgotten depopulated areas" tend to be distributed along the fringes of existing depopulated areas, it can be inferred that many of them are in close proximity to existing depopulated areas, but have become non-populated as a result of the leveling off of various requirements within the new municipality, and have now reached the present.