In a portable receiving device 1 operable with a battery 18 as power supply and capable of receiving the TV broadcast outdoors, a CPU 13 detects the receiving level of the TV receiving unit 12 at timings set in the timer 24, compares the receiving level with a preset threshold level, turns off, when the receiving level becomes lower than a threshold level, the power supply to the TV receiving unit 12, subsequently detecting and performs, when the receiving level subsequently exceeds a threshold level, a control for resuming the power supply to the receiving unit 12. Thus, the power consumption in the TV receiving unit 12 when the TV radio wave receiving status is deteriorated is reduced.