Annotation: The scientific article considers the views of scientists on the definition of proof. Despite the fact that this topic has always remained relevant today in the current Code of Criminal Procedure of Ukraine there is still no disclosure of this term. In our opinion, this is a rather negative phenomenon, because evidence in criminal proceedings plays one of the key roles, because it is through the correct course of evidence that an innocent person can be protected from illegal convictions. We have proposed our own definition of this definition, which can be used at the legislative level.