Abstract: The present invention relates to amplifier combined digital amplifier using pulse width modulation and analog amplifier, and more particularly, to amplifier converting the analog input signal to pulse width modulation signal by comparing the analog input signal with triangle-wave, inputting the pulse width modulation signal to a dead time logic circuit, controlling the “ON”, and “OFF” operation of output transistor by output signal of the dead time logic circuit and converting the pulse width modulation signal of the output transistor to amplified analog signal using LC low pass filter. The present invention reduces the loss of efficiency of output transistor. Therefore the size of heat radiating plate can be easily reduced and amplifier with compact size can be accomplished by the present invention.