Disclosed is a communication apparatus connected to an analog public line, which can be actualized at low costs and can save its space. This communication apparatus includes a first communication means connected to a telephone line, for performing communications, and a connecting means for connecting a second communication means connected to the telephone line via the first communication means and thus performing communications. In this communication apparatus, the first communication means has a first switch means for connecting the telephone line to the first communication means or the second communication means, a first route means for connecting the second communication means to the telephone line via the first switch means, a second route means for connecting the second communication means directly to the telephone line, a second switch means for connecting the second communication means to the first route means or the second route means, a first hook detecting means connected to the first route means, and a second hook detecting means connected between the telephone line on the second route means and the second switch means.