From the government’s perspective, it is important to understand the factors that influence effective utilization of new service channels, particularly the use of smart devices. Furthermore, how the utilization of a new channel affects trust in the government is an important performance factor whose linkage mechanism also needs to be investigated. This study collected 417 questionnaires from Korean citizens who communicate with the government via smart devices; the questionnaires were analyzed using structural equation analysis. This research indicates that in order to maximize trust in government, service delivery via smart devices must be designed with a clear understanding of the three significant components of such communication, namely the service, channel, and citizens. The service selected must be appropriate to the characteristics of the channel, and service reform may be necessary, beyond using the channel simply as a service means. Citizens’ ability to utilize the channel must also be fully considered. In order to increase the efficacy of new channel utilization, fast implementation is less important than understanding how to satisfy citizens’ needs regarding use of the public service via a smart device.