© 2019, Springer Nature Switzerland AG. Internet of Things (IoT) is highly expected to contribute in making elderly people’s quality of life better, especially by detecting early health risks and supporting livings. However, most elderly people are not friendly to IoT technologies, which is a barrier to implement IoT technologies into the elderly people’ livings. In this study, we designed a card-based age-friendly workshop to help elderly people being friendly and having confidence with IoT. The cards composed of 16 “trigger cards” and 14 “feedback cards” about several IoT devices, which reflects our degraded but age-friendly explanation of IoT that IoT devices give a “feedback” when a “trigger” happens. The participants were asked to come up with ideas for use cases of IoT by combining a trigger card with a feedback card. Within three workshops, 22 people of 65 years of age or older were recruited, and 134 ideas were totally obtained. We revealed that the ideas were categorized into nine groups based on the purpose of each use case. Moreover, survey results indicated that the elderlies became friendly with IoT through coming up with ideas in the workshop. In this study, we confirmed that carefully designed cards and example ideas can help participants bring out more ideas and higher confidence in IoT. Experiencing and imaging about the use of IoT in their own personal needs will encourage elderlies to use IoT technologies.