Although public exams and pedagogic corpora have practical values for language teaching and learning, few studies have been made on how to use such exams in the classroom and on how students use the corpora. In addition, in order to develop student-centered corpus tasks, students` attitudes toward pedagogic corpus use need to be investigated further. The purposes of this study were to examine how Korean high school students use Nationwide English Test Corpus (NETC), what is useful and what is problematic with using NETC and a corpus analysis tool, and whether students have positive or negative attitudes toward the corpus use. Before using NETC, 14 voluntary students were trained with genre-specific subcorpora. After the training, the students proofread their essays using NETC. Through a triangulation of the questionnaire survey, semi-structured interview, and observation of the self-editing process, the results revealed that students considered the corpora to be helpful while editing their essays. In addition, the students felt they gained valuable experience through the corpus use. Although there were largely positive attitudes, it appeared to be hard for the students to find synonyms and technical terms from the monolingual NETC. To overcome these limitations and problems, various corpus tasks need to be developed, and alternative versions of pedagogic corpora (perhaps multilingual corpora) need to be compiled.