To obtain a phase detector provided with a normalizing processing function that corrects a spike phase noise included in an input signal in the case of measuring waveform quality of a CDMA modulation signal.

A comparator 8 compares a phase of a normalizing signal of an output of a phase of an input signal with a phase of a normalizing signal of an output of a phase of an ideal signal received respectively from normalizing sections 6, 7, and outputs a phase signal as a result of comparison to a normalizing section 9. The normalizing section 9 detects a point, at which an error of ±π [rad] or over takes place from the phase signal received from the comparator 8, adds ±2π [rad] to the normalizing signal of the output of the phase of the input signal received from the normalizing section 6 after the detection point, and applies normalization again to the result and outputs the result.