Two types of array antennas having different down tilt angles are used separately between the outside and inside of the cell in consideration of the transmission mode. A base station apparatus is a base station apparatus that performs wireless communications with a mobile station apparatus, and has a first array antenna 201 having a down tilt angle of θ1 to perform MIMO (Multiple Input Multiple Output), and a second array antenna 202 having a down tilt angle of θ2 smaller than that of the first array antenna 201 to perform beam forming.