This study examined the effects of rice muffins added chestnut inner shell powder on the quality characteristics and antioxidant activity. Chestnut inner shell powder was added at 0, 1, 3, 5, and 7% of the weight of the rice flour, replacing rice flour. The moisture content and pH of the muffins added with chestnut inner shell powder were the highest in control and decreased as more chestnut inner shell powder was added. The weight decreased as the amount of chestnut inner shell powder added increased, and the volume, specific volume, and baking loss rate decreased as the amount added increased. Regarding the chromaticity, the L * and b * values decreased, and the a value increased. The polyphenol and flavonoid contents, the DPPH and ABTS + radical scavenging abilities, and reducing power significantly increased as the content of chestnut inner shell powder increased. As a result of the sensory evaluation, the overall preference for muffins added with chestnut inner shell powder was the highest in the group with 5% chestnut inner shell powder added. Therefore, when adding chestnut inner shell powder to muffins, it is best to add 3∼5% in terms of quality characteristics and preference. In this study, bakery products were developed using rice, and the applicability of chestnut inner shell powder as a functional material was confirmed.