In this study, a new phase measurement setup to measure magnitudes and phases of the fundamental components and intermodulation created by an amplifier under two tone excitation is reported. There are three signal generators, one digital attenuator and one spectrum analyzer in the measurement setup. There is no need to any other special electronic circuits (e.g., mixer, filter, etc.). Phase is found/measured mathematically based on magnitude measurements. Also absolute phase difference between the frequency components can be measured. Measured phase error is better than 1 degrees for repetitive measurements.