行政法上權利或義務，在特定條件下將發生由原歸屬之權利主體，移轉至另一權利主體之「繼受」情形。此在公法上不當得利返還義務領域，亦不排除有發生之可能性。在我國行政作業及爭訟實務上，最常發生之案例則為人民基於授益行政處分所受領之公法上金錢給付，因自始或嗣後無法律上之原因，致不當得利。惟受益人於返還前死亡，行政機關遂轉而向「繼承人」行使不當得利返還請求權。行政機關對人民之公法上不當得利返還請求權得否對其繼承人行使，應取決於原授益處分之效力是否具可繼受性，以及是否存有繼受之法律依據。本文認為人民之公法上不當得利返還義務應與行政機關原先許可發放之金錢給付脫勾觀察，並因其內容僅屬所受領金錢之返還而已，故不具一身專屬性，而可一般性地為繼承人所繼受。又有鑑於公法上不當得利返還義務係因無法律上原因而受有金錢給付之前行為所引起，充其量僅為回復原有之合法秩序而已，並未對受領人及其繼受人造成額外之權益負擔，故應可類推適用民法第1148條規定，作為該義務繼受之法律依據。縱然民法第1148條之繼承規定可作為行政法上權利義務繼受之一般法律依據，然本文認為由其卻無法導出包含有賦予行政機關以「給付裁決」之單方下命行政行為，實現公法上不當得利返還請求權之一般性行為形式授權。故在無特別法明文規定之情形下，行政機關因欠缺法律依據，不得向繼承人以作成給付裁決之行為形式，實現其公法上不當得利請求權。

Rights or obligations on administrative laws, under some circumstances, might be transferd to another entity, which is called ＂inheritance＂, and this may also occurs in unjust enrichment under public law. The most standing case of unjust enrichment is when people received payment of money, granted by the administrative disposition, which is void ab initio or made ineffective. However, the beneficiary died before returing the payment, and the administrative authority changes its claim over the money to the successors. Under what condition could the administrative authority be able to make such claim depends on whether the effect of the preceding disposition could be inherited, and is there any legal basis for doing so. This article concludes that the obligation to return under unjust enrichment law and the payment of money given by the administrative authority should be considered seperately. Since it concerns only the return of money, which is not an exclusive obligation, it could be inherited by the successors. Moreover, the obligation to return under the unjust enrichment law is meant to restore the legal order, which would not cause extra burden on the benefitiary and his/her successors; therefore, article 1148 of the Civil Code shall be applied as the legal basis for the inheritance.