Abstract: The present invention relates to an apparatus and method for forming a silicon nitride film by performing plasma enhanced atomic layer deposition (PE-ALD) employing very high frequency (VHF). An atomic layer deposition apparatus according to an embodiment of the present invention may comprise: a chamber providing a space in which a process is performed; a substrate support unit for supporting a substrate in the chamber; a gas supply unit for supplying gas to the chamber; an exhaust unit for discharging gas in the chamber; a plasma generation unit installed in the chamber to generate plasma in the chamber; and a VHF (very high frequency) power source for applying a VHF band signal to the plasma generation unit.