In spite of having highly developed technology, the majority of people feel too uncomfortable with the technology to use it efficiently. This problem is intimately linked with the interface design of the products. The role of interface design is to communication between people and the technical product such as a cellular phone, computer, or PDA. To use the product successfully, the interface design should be easy to use. The objective of this research is to create a practical and user-friendly interface design for a wireless device to control home appliances. In order to control home appliances with a cellular phone, the author suggests a intuitive interface design that is friendly and attractive to users, based on their experience, and effectively uses graphic elements such as layout, icon, color, and text. A usability test was conducted to determine problems people have while using the prototype. The results of the usability test indicated that the user interface was successful, and participants were satisfied with the prototype.