The article considers inheritance affidavit as a means of evidence in the context of changes introduced by the Act of 4 July 2019 amending the Code of Civil Procedure and certain other acts. This will apply in particular to the new Article 2711 of the Code. Pursuant to the mentioned regulation, a witness may give his/her testimony in writing under the conditions specified therein. The question arises as to the scope of the latter regulation, in particular whether it covers e.g. the evidence from the parties testimony and the inheritance affidavit. The analysis of these issues is historical and comparative in specific regarding German and French legal systems.