A liquid surface condition detector comprising: an irradiation unit configured to irradiate with light a container storing a liquid substance and a liquid surface of the liquid substance from above; an imaging unit configured to capture, from above, an image of the liquid substance subjected to light irradiation by the irradiation unit; and a first liquid surface detector adapted to detect bubbles on the surface of the liquid substance using color or brightness information contained in the image; characterized in that the first liquid surface detector is adapted to detect bubbles on the surface of the liquid substance using color information contained in the image by counting and determining the number of isolated mirror-reflection regions in the image having color information corresponding to the color of the light irradiated from the irradiation unit; and the liquid surface condition detector further comprises a second liquid surface detector adapted to detect bubbles on the surface of the liquid substance using brightness information contained in the image by calculating a brightness gradient in a direction along an inner wall surface configuration of the container from the image; and a mode selector for selecting, by use of the color information contained in the image, which of the first and second liquid surface detectors is to be used for detecting bubbles on the surface of the liquid substance. an irradiation unit configured to irradiate with light a container storing a liquid substance and a liquid surface of the liquid substance from above; an imaging unit configured to capture, from above, an image of the liquid substance subjected to light irradiation by the irradiation unit; and a first liquid surface detector adapted to detect bubbles on the surface of the liquid substance using color or brightness information contained in the image; characterized in that the first liquid surface detector is adapted to detect bubbles on the surface of the liquid substance using color information contained in the image by counting and determining the number of isolated mirror-reflection regions in the image having color information corresponding to the color of the light irradiated from the irradiation unit; and the liquid surface condition detector further comprises a second liquid surface detector adapted to detect bubbles on the surface of the liquid substance using brightness information contained in the image by calculating a brightness gradient in a direction along an inner wall surface configuration of the container from the image; and a mode selector for selecting, by use of the color information contained in the image, which of the first and second liquid surface detectors is to be used for detecting bubbles on the surface of the liquid substance. a second liquid surface detector adapted to detect bubbles on the surface of the liquid substance using brightness information contained in the image by calculating a brightness gradient in a direction along an inner wall surface configuration of the container from the image; and a mode selector for selecting, by use of the color information contained in the image, which of the first and second liquid surface detectors is to be used for detecting bubbles on the surface of the liquid substance. <EOS>