The present invention provides a pretilt angle measurement device and a pretilt angle measurement method which can restrain errors. The pretilt angle measurement device 1 comprises a transmission measurement light irradiating part 2 of irradiating the polarized measurement light to a measurement position M of a liquid crystal substrate LC; a transmission measurement light reception part 3 for receiving the transmission light of the measurement light and obtaining the polarization state of the transmission light; a tilt measurement light irradiating part 41 for irradiating the detection light to the measurement position M of the liquid crystal substrate LC; a tilt measurement light reception part 43 for receiving the reflected light L2 of the detection light L1 and obtaining the light reception position of the reflected light L2; and a control part 10 for calculating the tilt angle of the measurement position M of the liquid crystal substrate LC according to the light reception position of the reflected light L2, and calculating the pre-tilt angles of the liquid crystal molecules contained in the liquid crystal substrate LC according to the irradiation angle of the measurement light, the tilt angle at the measurement position M of the liquid crystal substrate LC and the polarization state of the transmission light.