The concept of "digital evidence" is a new concept in criminal procedure law. Digital evidences which correspond to "data, records and documents created/modified/saved in electronic environment and used for investigation of a criminal act" are generated in the form of "numerical data" and -thus- lead to several problems in practice in terms of "reliability". It is needed to gather digital evidence duly (in accordance with legal requirements), which -like all other evidence-serve to reveal the material facts, as a result of the principle of freedom of evidence. It must be stated that art. 134-138 of (Turkish) Criminal Procedure Code should be partially amended, and an instution specialized in the area of digital forensics ought to be constituted for tackling problems in practice.