A radio base station is operable to transmit to a radio terminal a measurement configuration message for causing the radio terminal to perform a logging process of storing a measurement log including a measurement result of a radio environment, and to acquire the measurement log stored by the radio terminal. The radio base station includes a receiver configured to receive, from the radio terminal, log storing information indicating that the measurement log is stored in the radio terminal, and a transmitter configured to transmit, to the radio terminal, a log transmission request to request a transmission of the measurement log on the basis of the log storing information. The receiver is configured to receive, from the radio terminal, a log transmission response for carrying the measurement log and the log transmission response even when the measurement log is not stored in the radio terminal.