The telecommunication service industry plays a major role in the realization of the perfect information society in the 21st century and, has a great influence in society and culture. Using the Calculable General Equilibrium Model, we analyze the telecommunication service's economic effects on other industries as well as on the national economy. In 2001, the 8 percent increase in the telecom sales caused the 5 billion dollar increase in the GDP, which seems to continue to bring about no less than 5 billion dollar GDP increase each year until 2030. The telecom sales increase has been evaluated to have disproportionately positive effect on transmission device and audio equipment industries. In summary, the telecom sales have a positive net effect on the GDP and on most of the industries with a few exceptions.