To provide a transmitter for reducing the consumption of the capacity of a battery cell, and for preliminarily escaping the shortening of a time for communication, even at operation of communication in a situation where the temperature is relatively low.

In a portable telephone device 1, when detecting that the temperature of a battery cell 10 is less than a set temperature, a control part 12 reduces the amplification factor of a variable amplifier 16 for making the radiation level of transmission radio waves to be radiated from an antenna 8 smaller than a reference radiation level. Thus, a power level to be supplied from the battery cell 10 to a transmitting part 13 can becomes smaller than the reference power level, and the consumption of the capacity of the battery cell 10 can be reduced.