Signal timing adjustment in an amplifying device is appropriately performed by phase adjustment by a digital filter. The amplifying device includes an amplifier; an amplitude-voltage converting unit 12 that performs a desired process on a signal relating to operation of the amplifier, whereby the signal is band-broadened; and a timing adjusting unit 15a that performs timing adjustment of the signal to be provided to the amplifier, by phase adjustment by a digital filter. The timing adjusting unit 15a performs the timing adjustment of the signal at a stage before the signal is band-broadened by the amplitude-voltage converting unit 12.