An orientation characteristic measurement method of calculating an orientation parameter of a sample made of an organic electro luminescence material having a predetermined refractive index and disposed with a predetermined film thickness on a light transmitting substrate using an irradiation optical system configured to irradiate the sample with irradiation light, a detection optical system configured to guide fluorescent detection light emitted from the sample by the irradiation of the irradiation light, and a light detector configured to detect the fluorescent detection light, the orientation characteristic measurement method comprising: a detection step of detecting the fluorescent detection light using the light detector while changing a formed angle (φ) between a line perpendicular to a surface of the sample on the emitting side of the fluorescent detection light and an optical axis of the detection optical system, and outputting an angle dependent distribution of the fluorescent detection signal; an acquisition step of normalizing the fluorescent light intensity detected at a formed angle (φ) taken in a predetermined angle range with the fluorescent light intensity detected when the formed angle (φ) is 0°, so as to acquire a normalized angle-dependent distribution of the fluorescent light intensity obtained from the fluorescent detection signal a specifying step of specifying fluorescent light intensity in a maximum area in which the fluorescent intensity value is maximized, wherein the maximum area is present between an angle at which the fluorescent light intensity is minimized and 90° on the basis of the normalized angle-dependent distribution of the fluorescent light intensity; a selection and determination step of selecting and determining a linear relationship between the reciprocal (RI 0) of the specified fluorescent light intensity in the maximum area after normalization and a Z component (μ z) of a dipole moment of the sample corresponding to the component of the dipole moment in the direction of the predetermined film thickness, wherein the Z component (μ z) is determined using the specified fluorescent light intensity and the selected linear relationship, wherein the linear relationship is selected from among a plurality of linear relationships stored for respective combinations of a plurality of film thicknesses and a plurality of refractive indexes in advance on the basis of values of the predetermined refractive index and the predetermined film thickness of the sample input from a user; a calculation step of calculating the orientation parameter on the basis of the derived Z component (μ z) of the dipole moment of the sample, and wherein the orientation parameter is calculated based on the following equation: S = μ z 2 − 1 / 4 1 − μ z 2 / μ z 2 + 1 / 2 1 − μ z 2. a detection step of detecting the fluorescent detection light using the light detector while changing a formed angle (φ) between a line perpendicular to a surface of the sample on the emitting side of the fluorescent detection light and an optical axis of the detection optical system, and outputting an angle dependent distribution of the fluorescent detection signal; an acquisition step of normalizing the fluorescent light intensity detected at a formed angle (φ) taken in a predetermined angle range with the fluorescent light intensity detected when the formed angle (φ) is 0°, so as to acquire a normalized angle-dependent distribution of the fluorescent light intensity obtained from the fluorescent detection signal a specifying step of specifying fluorescent light intensity in a maximum area in which the fluorescent intensity value is maximized, wherein the maximum area is present between an angle at which the fluorescent light intensity is minimized and 90° on the basis of the normalized angle-dependent distribution of the fluorescent light intensity; a selection and determination step of selecting and determining a linear relationship between the reciprocal (RI 0) of the specified fluorescent light intensity in the maximum area after normalization and a Z component (μ z) of a dipole moment of the sample corresponding to the component of the dipole moment in the direction of the predetermined film thickness, wherein the Z component (μ z) is determined using the specified fluorescent light intensity and the selected linear relationship, wherein the linear relationship is selected from among a plurality of linear relationships stored for respective combinations of a plurality of film thicknesses and a plurality of refractive indexes in advance on the basis of values of the predetermined refractive index and the predetermined film thickness of the sample input from a user; a calculation step of calculating the orientation parameter on the basis of the derived Z component (μ z) of the dipole moment of the sample, and wherein the orientation parameter is calculated based on the following equation: S = μ z 2 − 1 / 4 1 − μ z 2 / μ z 2 + 1 / 2 1 − μ z 2.