Fluorescence polarization measurement device, and degree of polarization measurement method

A fluorescence polarization measurement device, comprising:

• a light source unit that emits excitation light that is linearly polarized;
• a polarization direction modulation element that spatially modulates a polarization direction of the excitation light by a predetermined frequency, and emits, on a measurement target solution, the excitation light for which the polarization direction is spatially modulated by the predetermined frequency;
• a detector that detects a spatial distribution of fluorescence intensity of the fluorescence having a polarization direction in a predetermined direction from among fluorescence emitted from the measurement target solution due to the excitation light for which the polarization direction is spatially modulated by the predetermined frequency;
• and
• a controller that extracts, from the detected spatial distribution of fluorescence intensity, a direct current component and a component having a frequency identical to the predetermined frequency, and calculates, based on the extracted component and the direct current component, a degree of polarization of the measurement target solution.