An amplification device includes a pulse signal acquisition part, a dummy signal generation part, a combination part, an amplifier and a separation part. The pulse signal acquisition part acquires a desired signal that is a pulse signal to be amplified. The dummy signal generation part generates a dummy signal. The combination part adds the dummy signal before and after the desired signal and outputs a composite signal. The amplifier amplifies the composite signal and outputs an amplified composite signal. The separation part extracts an amplified desired signal that is a signal resulting from amplification of the desired signal, from the amplified composite signal and outputs the amplified desired signal. Power of the composite signal is power that makes the amplification part operate nonlinearly.