A T-SIR generation unit (106a) generates, on the basis of an actual reception quality (205) in a mobile communication terminal, a target value T-SIR to be used to control transmission power of a base station from the mobile communication terminal. When the mobile communication terminal exists in the service area of a predetermined specific communication carrier, a T-SIR correction unit (106b) adds a correction value K to the T-SIR generated by the T-SIR generation unit (106a). Even when a reception SIR abruptly deteriorates in a communication carrier with a strong reception field and a low BLER, it does not drop below the SIR limit value of the mobile communication terminal. Hence, the terminal can receive the signal from the base station and continue a service such as speech communication. When a long-term BLER measurement result is used instead of a BER, stable transmission power control can be done normally.