Conventional IT device has been evolving into smart device based on more powerful computing, the adoption of platforms, and next generation networking. There are not many empirical studies with regard to the early adoption stage of smart IT technology devices. This paper aims to investigate intention to use smart device based an extended technology acceptance model (TAM) with flow empirically. We get the results that there are positive influences among multidimensional user characteristics and flow, perceived usefulness and the intention to use. According to this results, companies which want to dominate the market in advance should understand the characteristics of potential consumers in developing marketing strategies and contents.