A power amplifying apparatus includes a high-speed low pass filter (10) which inputs an envelope signal included in a transmission signal therein, a low-speed low pass filter (11) which inputs the envelope signal therein, a determination unit (12) which inputs the envelope signal therein and determines rising or falling of the envelope signal, a selecting unit (13) which selects one of the high-speed low pass filter (10) and the low-speed low pass filter (11) according to a determined result of the determination unit (12), and a voltage supply unit (4) which generates a voltage based on a signal input according to a selection by the selecting unit (13) and supplies the voltage to a power amplifier (5) which inputs the transmission signal therein so as to amplify a power of the transmission signal.