 He was at the old theological institute of Nikolaihaus for a brief period before moving to the new Canisianum.Apor was made a subdeacon on 22 August 1915 and was elevated to the diaconate on 23 August.He received his ordination to the priesthood on 24 August 1915 and he celebrated his first Mass on 25 August with his mother and sisters Henrietta and Gizella in attendance.