The voluntary abandonment which the punishment should be decreased and exempted is the legal theory that is profitable for the criminal defendant. This thesis has the start point that though `free will' as an abstract concept has a limit to get the concrete outcome, the substance of the abandonment is `free will' because the process
judging whether some case is an voluntary abandonment or not is based on the defendant's subjective understanding. This thesis also puts stress on the success of the abandonment activity. Therefore this thesis aims at establishing the free will investigation process as follows. In the side of the order, the success or failure of the
activity will be confirmed at first. Then only giving up case not punished is reviewed theoretically to confirm its operational function in the free will investigation process. At the stage of the free will investigation, the existing eclecticisim strengthens its contents in the way that it compensates the Frank-formal for the performer's understanding, the Social Conception Theory for the judgment standard, the Autonomous Motivation
Theory for the autonomy of the decision, and the Legal Conception Theory for its legal linguistic frame.