The copyright infringement case between Google and Oracle ended with Google's victory by deciding that its use constitutes fair use. Although there are strong objections to this ruling, the majority view is valid for the following reasons: First of all, the declaration code is a method of operation, so it is not copyrightable by Article 102(b), and even if it can be protected, copyright protection is not achieved because protection range is very narrow, so fair use should be applied easily. Furthermore, the creativity of declaration code corresponds to technical creativity, and protection under copyright law cannot be recognized, even if there are many other expressions. In addition, fair use should be made in consideration of the public interest for the purposes of copyright law, i.e. the protection of programmers or the provision of new innovative tools. Applying these methods of fair use judgement to work, that is, article 102(b), excluding technical creativity from copyright protection, considering public interest as an individual factor would also play a major role in reducing unpredictability and uncertainty that is the biggest problem in fair use judgement. And these fair use criteria and methods could be a number of guidance for our country with the same provisions of the law, especially the restriction on protection of copyright and the consideration of public interests factors.