A communication apparatus including: a frame; a transmission line connectable to a public line network; a print circuit board including a frame ground terminal portion and configured such that a dielectric strength between the transmission line and the frame ground terminal portion takes a specific value in a state in which elements are connected to between the transmission line and the frame ground terminal portion via conductor patterns. The frame ground terminal portion includes: a first land formed on a first conductor pattern formed on a face of the print circuit board, a surge protection element being connected to the first conductor pattern; and a second land formed on a second conductor pattern formed on the face, elements different from the surge protection element being connected to the second conductor pattern. The first and second lands contacts the frame by fixing of the print circuit board to the frame.