Since the 7th educational renovation was established, ICT has emerged as an indispensable tool for teaching a variety of subjects in junior and high schools. This paper gives a brief description about the current level of ICT use in junior high schools and develops the model for explaining the factors affecting the use of ICT in classrooms. Based on data collected from a questionnaire survey from junior high schools teachers in northern part of Kyunggi province, a following conclusion is provided: the perceived usefulness, ease of use does not significantly affect the level of satisfaction, which is relatively low due to ineffective training and support. But the attitude and norm affect the level of the perceived usefulness, and the attitude and self-efficacy affect the ease of use. The result from analysis might provide the useful directions for effectively diffusing the ICT use in junior high schools.