Through students’ attitudes toward class and controlled for academic achievement’s influencing factors, this study analyzed the influence of the use of digital devices in classrooms on achievement in each subject. Data from the second and third years of the elementary school panel of the Daegu Education Longitudinal Study 2021 were analyzed by applying a structural regression model. Through their classroom attitude, digital use positively affected elementary students' math and Korean achievement. In other words, the higher their assignment feedback, the more positive their attitude toward class; the better their attitude toward class, the higher their academic achievement. In addition to its mediating effect, digital use had a significant direct effect on Korean language achievement. On the contrary, attitude toward class fully mediated digital use’s effect on mathematics achievement. This trend was significant even when prior achievement and related factors’ influence were considered. Research results indicated the need to create a digital educational environment and strengthen related support so that various teaching methods using digital devices can be developed and used during classes in elementary schools. Results also indicated that additional research should be conducted at the regional, school, and school levels.