An apparatus and a method for measuring an electric magnetic interference (EMI) level of a radio frequency device is disclosed. The apparatus for measuring a level of electric magnetic interference (EMI) with an electronic device to radiate an electromagnetic wave, the apparatus including: a test device for outputting a signal in response to the electromagnetic wave radiated from the electric device; a calculating unit for calculating a group_delay variation information of the test device by using the signal from the test device; a processor for storing a reference group_delay variation; and an analyzer for analyzing the level of EMI by comparing the reference group_delay variation information and the group_delay variation information.