A communication apparatus for performing a communication with other communication apparatus by using identification information, includes a housing, a plurality of grounding terminals which are respectively connected to one ends of internal grounding lines provided within the housing for connecting to an external grounding line outside the housing, a grounding line connection detection section which detects a grounding terminal connected to the external grounding line among the plurality of grounding terminals, and an identification information setting section which sets the identification information based on a detection result of the grounding line connection detection section.