The invention relates to a semiconductor device, radio communication device, and control method for radio communication device. A semiconductor device capable of reducing its power consumption is provided. A semiconductor device includes a receiving unit that receives a radio signal, a received signal strength measurement unit that measures a signal strength of the radio signal received by the receiving unit, a threshold comparison unit that compares the received signal strength measured by the received signal strength measurement unit with a threshold, a demodulation unit that demodulates the radio signal received by the receiving unit based on a result of the comparison, and a threshold setting unit that sets the threshold according to the received signal strength measured by the received signal strength measurement unit.