When a signal having two or more frequency components is fed to a circuit to be measured, a phase of the signal output from the circuit to be measured is measured. A phase measurement device measures an output when an input signal having two input frequency components ω10 and ω20 is fed to an amplifier (circuit to be measured). The phase measurement device includes an orthogonal converter that subjects the output of the amplifier to an orthogonal conversion using an average frequency ω0, which is an average of ω10 and ω20. A phase acquisitioner acquires phases θ1 and θ2 of the input frequency components in the output of the orthogonal converter and a phase θ3 of a distortion component. A match time/phase measurer measures a match time Δt during which phase θ1 is matched with phase θ2, and measures phase θ1 (Δt) during that time. A distortion component phase measurer measures phase θ3 (Δt) of the distortion component in the match time Δt. A display then displays θ1 (Δt) and θ3 (Δt).