A base station apparatus is disclosed that is capable of communicating with a user equipment terminal using a shared channel in downlink and controlling transmission power of a control channel reporting identification information of the user equipment terminal receiving the shared channel and a transmission format of the shared channel. The base station apparatus includes a transmission power control unit configured to control the transmission power of the control channel based on downlink radio quality information reported from the user equipment terminal and an offset value determined based on communications quality of the control channel.