A liquid level detection device comprising: an irradiation unit configured to irradiate a side surface of a sample container containing a sample having layers with light; a light receiving unit configured to receive transmitted light that is the light emitted from the irradiation unit and passing through the sample container; an analysis unit configured to acquire an interface between the layers of the sample contained in the sample container based on received amounts of the transmitted light received by the light receiving unit; a first drive unit (150; 151) configured to move the sample container in a vertical direction relative to the irradiation unit and the light receiving unit or to move the irradiation unit and the light receiving unit in the vertical direction of the sample container; a second drive unit (160; 161) configured to move the sample container in a circumferential direction of the sample container relative to the irradiation unit and the light receiving unit or to rotate the irradiation unit and the light receiving unit about the vertical direction of the sample container as a rotation axis; and a control unit configured to control the first drive unit (150; 151) and the second drive unit (160; 161), wherein the control unit controls the second drive unit (160; 161), so that the irradiation unit irradiates the sample container with the light at a first irradiation angle and a second irradiation angle different from the first irradiation angle, and the light receiving unit receives transmitted light that is the light passing through the sample container, and the analysis unit acquires an interface between the layers of the sample based on received amounts of transmitted light at the first irradiation angle and the second irradiation angle, characterised in that the liquid level detection device is adapted to determine a type of a separator contained in the sample, the analysis unit is adapted to use a first interface calculation method when the separator is identified as a gel, as beads, or as no separator at all, the analysis unit is adapted to use a second interface calculation method when the separator is a mechanical separator, and the second interface calculation method is different from the first interface calculation method. an irradiation unit configured to irradiate a side surface of a sample container containing a sample having layers with light; a light receiving unit configured to receive transmitted light that is the light emitted from the irradiation unit and passing through the sample container; an analysis unit configured to acquire an interface between the layers of the sample contained in the sample container based on received amounts of the transmitted light received by the light receiving unit; a first drive unit (150; 151) configured to move the sample container in a vertical direction relative to the irradiation unit and the light receiving unit or to move the irradiation unit and the light receiving unit in the vertical direction of the sample container; a second drive unit (160; 161) configured to move the sample container in a circumferential direction of the sample container relative to the irradiation unit and the light receiving unit or to rotate the irradiation unit and the light receiving unit about the vertical direction of the sample container as a rotation axis; and a control unit configured to control the first drive unit (150; 151) and the second drive unit (160; 161), wherein the control unit controls the second drive unit (160; 161), so that the irradiation unit irradiates the sample container with the light at a first irradiation angle and a second irradiation angle different from the first irradiation angle, and the light receiving unit receives transmitted light that is the light passing through the sample container, and the analysis unit acquires an interface between the layers of the sample based on received amounts of transmitted light at the first irradiation angle and the second irradiation angle, characterised in that the liquid level detection device is adapted to determine a type of a separator contained in the sample, the analysis unit is adapted to use a first interface calculation method when the separator is identified as a gel, as beads, or as no separator at all, the analysis unit is adapted to use a second interface calculation method when the separator is a mechanical separator, and the second interface calculation method is different from the first interface calculation method.