A signal inverting device generates an inverted signal of an input signal. The device includes a normally-on transistor, a negative-voltage generating unit that generates a negative voltage, and an output terminal. A first terminal of the normally-on transistor is connected to a current source. The output terminal is connected between the first terminal of the normally-on transistor and the current source. The normally-on transistor is turned on/off, by an input of a drive signal to a conduction control terminal of the normally-on transistor. The drive signal is a signal obtained by a synthesis of the input signal and the negative voltage. The inverted signal is output from the output terminal in accordance with the on/off operation of the normally-on transistor. The negative-voltage generating unit generates the negative voltage by rectifying a high-frequency power.
