Households diffusion rate of PC have been declining for some years; however, it is still an important device for web-service such as e-commerce. In this study, a cohort analysis of private PC usage was conducted to determine the future of PC as an internet device. The analysis result indicates that there is a gender difference in terms of the PC usage. From age twenty to sixty men are relatively high in the frequency of PC usage. On the other hand, 1953-born or older female are significantly less frequent PC users. Meanwhile, female born in 1964 to 1990 are very frequent PC users. Therefore, it is expected that the frequency of PC usage by older female will rise with ageing of 1964-to-1990-born female group.