This invention provides a power amplifier (100) including a signal source control unit (110) which generates and outputs an amplitude signal serving as the amplitude modulated component of an input signal and a pulse modulated signal based on the amplitude signal, and outputs a transmission signal obtained by superposing the input signal on a carrier, a delay adjustment unit (120) which synchronizes the amplitude signal, pulse modulated signal, and transmission signal with each other, a voltage signal generation unit (130) which outputs a voltage signal corresponding to the amplitude signal synchronized with the transmission signal, a current signal generation unit (140) which outputs a current signal corresponding to the pulse modulated signal synchronized with the transmission signal, and a transmission signal amplification unit (150) which amplifies the transmission signal, and outputs a transmission signal obtained by modulating the amplitude of the amplified transmission signal based on a modulated power supply signal generated by synchronizing the voltage signal and the current signal. The power amplifier can ensure the precision of the transmission signal, reduce the power consumption by using a compact, low-cost circuit arrangement, and increase the power efficiency more than the conventional one.