COMMUNICATION APPARATUS AND COMMUNICATION SYSTEM

To provide a communication apparatus (10) in which the deterioration of the antenna characteristics of a second antenna (11) for backup is suppressed.The communication apparatus (10) electrically connected to a first antenna (20) through a first cable (22) is characterized by including: the second antenna (11) configured to be substitutable for the first antenna (20); a first ground portion (15a) to which a second cable (23) for grounding the first antenna (20) is connected; an antenna detection circuit (14) configured to detect a state of the first antenna (20); an antenna switching unit (12) configured to switch from the first antenna (20) to the second antenna (11), in a case where the antenna detection circuit (14) detects an abnormality of the first antenna (20); and an insulating portion (16) configured to insulate the first ground portion (15a) from a second ground portion (15b) around the first ground portion (15a), in a case where the antenna detection circuit (14) detects an abnormality of the first antenna (20).