Abstract: This research, which we have in hand, examines the main general principle in criminal evidence, which is the principle of self-conviction of the criminal judge, and through this principle, we will discuss the nature of the principle of self-conviction in terms of its definition, explanation of its justifications and related provisions and scope of this principle, then exposure to restrictions And the exceptions to this principle, and then we show the practical application of this principle to the evidence of evidence in the criminal case, namely confession, testimony, experience, clues, and written evidence, using the opinion of jurisprudence, judiciary and comparative legislation, and then in the end we put a conclusion in which a summary of the research in addition to a set of results And recommendations desired Keywords: Self-conviction || Criminal judge || The conviction of the criminal judge