When a fluticasone propionate (FP) diskhaler is used to administer inhaled corticosteroid, it has been reported that there is considerable drug residue remaining in the diskhaler after use. The internal structure of the diskhaler is complex, and it is possible that sufficient cleaning of the device is not achieved using the attached brush. In this study, the diskhaler cleaning method was examined using a patient questionnaire. In response to the question on cleaning, 56.3% of patients responded "Having done", and 66.7% responded to the question on the frequency of the cleaning, "When I use it". Furthermore, cleaning by a healthy volunteer was examined using Rotadisk for inhalation practice. When the group that did not perform cleaning was compared with the group that performed cleaning with the brush, the amount of the lactose adhesion was significantly lower in the cleaning group. When the no-cleaning group was compared with the group that shook off the excess residue from the tray and the main body of the diskhaler, the group that shook off the diskhaler components showed a significantly lower amount of lactose adhesion. It was confirmed that drug residue were able to accumulate, and the shaking off method appeared to have an effect equal to that of cleaning with the brush. It seems that providing patients with guidance not only about the method of inhaling with the diskhaler but also about cleaning of the device is an important area of pharmacy patient management.