The problem of population decline and local annihilation is directly linked to the problems of national existence and balanced national development. Despite massive fiscal and population growth policies to solve the problem of low fertility and aging according to the Framework Act on Low Fertility and Aging, the population fertility rate is 0.81 in 2021, which is the lowest in the world. As the phenomenon of concentration in the metropolitan area accelerated due to a decrease in local jobs and unbalanced development of the region, the Special Act on Balanced National Development, the Metropolitan Area Reorganization Planning Act, and the Local University Promotion Act have been enacted and implemented to solve the problem. development is not resolved. The government enacted the Special Act on Support for Depopulated Areas in June 2022 to respond to local annihilation. In the same law, local governments lead crisis response in areas with reduced population, national customized comprehensive support, strengthening cooperation between local governments and countries, and special provisions for childcare, medical care, housing, transportation, culture, and immigration in areas with reduced population is putting. Although it is necessary to distinguish between population reduction and local annihilation, the Special Act on Support for Depopulation Areas defines only the term “depopulation area” and does not define the concept of “local annihilation”. It is necessary to conceptually define a region that requires special social, economic, financial, and administrative measures from the state as local governments cannot survive on their own or are in danger of extinction as an area with a low population density. In this paper, after examining the main contents of Korea's Constitution, the Special Act on Balanced National Development, and the Special Act on Support for Depopulated Areas, to find implications for Korea and propose public law tasks by reviewing the Spanish Constitution and the legislative examples of Castile-La Mancha in Spain, present. First, although the Korean constitution provides for balanced national development, the principle of solidarity stipulated in Articles 2 and 138 of the Spanish Constitution is stipulated to provide positive preferential treatment to areas in danger of late extinction or concern, so that the lives of the residents of the area are made. quality should be improved. Second, shared accommodation through settlement subsidies, tax reductions, and vacant home village regeneration should be made to activate residential mobility and sedentity in areas with reduced population and local extinction. Third, the Special Act on Support for Areas with Decreased Population has special regulations regarding the establishment of childcare facilities and universities, hearing opinions from the heads of local governments when kindergartens and elementary schools are closed, subsidizing expenses, and special measures for school establishment. Since it is necessary to substantially guarantee the right to education and access to education, etc., legal and institutional arrangements should be made to ensure the right to access public education, maintain schools, guarantee equal access to education for students, internship programs, non-compulsory education programs, and vocational training. Fourth, since the expansion of jobs and local labor force is the key to recovering the lost population and suppressing the disappearance of local areas, it is possible to create effective and suitable jobs in the depleted areas, as well as incentives for workers in the depleted areas, and to develop public and private projects and projects. Promotion, deregulation, and simplification of administrative procedures, project projects and plan implementation management systems for local extinction areas, and funding programs (subsidies) should be introduced.