The rational choice of an inhalation device is a cornerstone in the effective management of asthma and COPD. In this publication, we describe the development of a new system, the Inhalation Manager, which, for the first time, offers the possibility to assess the entire inhalation maneuver of patients using original devices under everyday conditions. So far the Inhalation Manager allows the measurement of inspiratory maneuvers of patients through placebo inhalation devices of the most common breath-actuated CFC-free inhalers in the market for the three main glucocorticosteroids Budesonide [Turbohaler (TH), dry powder inhaler (DPI)], Beclomethasone dipropionate [Autohaler (AH), breath-actuated pressurized metered dose inhaler (pMDI)], and Fluticasone propionate [Diskus (DI), DPI] by means of a pneumotachometer. In addition, it allows allocation of the individual maneuver to the expected drug delivery values (mass output and particle size distribution) of these three devices. In a field trial, the inhalation technique of 628 (TH), 794 (AH), and 795 (DI) patients, respectively, was tested in 72 pulmonologist practices with the Inhalation Manager. For patients in the 18-59-year-old group, the Inhalation Manager detected the following percentages needing improvement: 1.5% for the Autohaler device, 16.7% for the Diskus, and 38.9% for the Turbohaler. In the 60-99-year-old group, percentages needing improvement were 1.5%, 31.5%, and 66.1% for the Autohaler, Diskus, and Turbohaler, respectively. Therefore, the Inhalation Manager could become an essential tool in asthma management by finding the most suitable inhaler for an individual patient and by training the optimal inhalation technique.