This study focused on the deconstruction of Mr. Gregg’s character in Roald Dahl’s The Magic Finger to find out the process of Mr. Gregg’s character deconstructed by Derrida’s deconstruction. This study used the qualitative-descriptive method to analyze the relationship between Mr. Gregg’s character in the story and Derrida’s deconstruction theory. The data of this study were the narration, dialogue, words, sentences, paragraphs, phrases, and quotes that related to Mr. Gregg’s character in The Magic Finger novel by Roald Dahl in 2016. In this study, the researcher analyzed Mr. Gregg’s character through binary oppositions which raise the opposite view of the fixed meaning. The findings show that there are six data found of five binary oppositions in the novel contradictory characteristics of Mr. Gregg. Previously, the fixed meaning of Mr. Gregg’s character: a bad, irresponsible, pessimistic, timid, and uneducated character. But after doing a deep analysis by using deconstruction theory, Mr. Gregg also showed the alternative meaning: a good, responsible, optimistic, brave, and educated character that Mr. Gregg privileges had a negative and positive side which makes the meaning of the character unpredictable or undecidable. This study showed that the meaning in the text never exists permanently or completely. Thus, the reader should not be trapped only in one perspective and this thing will build skepticism for the researcher who will analyze the literary study by using deconstruction theory.