This dissertation investigates in three parts the Supreme Tribunal of the Apostolic Signatura's competency of vigilance over proper administration of justice in the Church. The first part presents a historical-exegetical analysis, tracing the development of the charge of vigilance through the various legislative changes and curial re- forms, including the reestablishment of the Supreme Tribunal in 1908, the creation of the Officium vigilantiae at the Sacred Con- gregation for the Discipline of the Sacraments, the transfer of that munus vigilantiae to the Apostolic Signatura, and the promulgation of the Lex propria in 2008. The second part explores the Apostolic Signatura's praxis, fo- cusing the use of various faculties employed to confront grave ir- regularities according to the different stages of the judicial process, including precepts, case transfers, the suspension of the execution of a sentence, even double-conforming, and responses to other pe- titions and recourses. The third part offers a systematic analysis of the concept of vigi- lance with respect to the administration of justice, examining the competent authority, the object of vigilance, and the relationship between the two, as well as the powers associated with vigilance, its limits, and its purpose.