A communication apparatus and communication method

Having: a first antenna section (2) and the second antenna section (3); a switching unit (4), during a first selection of the first antenna section (2), during a second selection of the second antenna section (3); reception determining section (6), it is determined whether the communication data can be acquired first antenna section (2) or the second antenna section (3) of the received wireless signal includes a normal; and a storage unit (7), a plurality of communication terminals storing each of a first antenna section (2) and the second antenna section (3) of each of correspondence relationship, a switching unit (4), set the length of the first period and the second period, it is determined that the normal acquire a second antenna portion (3) corresponding to the number of communication terminals with communication data transmitted between the ratio of the number of times the normal acquisition of the first antenna section (2) corresponding to the communication terminal for transmitting communication data is determined, and during the second phase length equal to the ratio of the length of the first period.