Background. Atopic dermatitis control tool (ADCT) is a patient-reported measure to assess disease control of atopic dermatitis (AD), consisting of the severity of symptoms, itch duration, bother, sleep, daily activities, and mood/emotions. Objectives. We evaluated the alterations of total and individual ADCT item scores during treatment with Janus kinase 1 inhibitor upadacitinib in AD patients. Methods. Forty-seven patients aged >= 12 years with moderate-to-severe AD were treated with oral upadacitinib 15 mg/day plus topical corticosteroids. Total and individual ADCT item scores, eczema area, and severity index (EASI) and peak pruritus numerical rating scale (PP-NRS) were evaluated. Results. Before treatment, total ADCT correlated with EASI and PP-NRS. The median percent reduction at months 1, 3, and 6 of upadacitinib treatment was 80%, 76.2%, and 67.4% in total ADCT, 75.28%, 85.06%, and 81.73% in EASI, 66.67%, 75%, and 75% in PP-NRS, respectively, and percent reduction of total ADCT correlated with that of EASI and PP-NRS except for no correlations with that of EASI at month 1. The percent reduction of ADCT no.4 was the highest among the 6 items. Conclusions. These results suggest that changes in ADCT reflect the therapeutic effects of upadacitinib and that ADCT can be a treatment target for upadacitinib therapy. Upadacitinib might preferentially improve sleep disturbance.