A method and a device, for detecting a solid-liquid distribution in a solid-liquid separation column of a freeze concentration device, that are used when a freeze concentration method is performed is suggested. The device for detecting the solid-liquid distribution in the solid-liquid separation column of a solid-liquid separation device includes a light irradiation means for irradiating the inside of the solid-liquid separation column of the freeze concentration device with visible light, a photographing means for picking up an image of the inside of the solid-liquid separation column irradiated with the visible light by the light irradiation means, a movement means for moving the photographing means in an up-and-down direction of the solid-liquid separation column, an image analysis means for analyzing a data piece of an image picked up by the photographing means and a determination means for determining a solid-liquid distribution state in the solid-liquid separation column based on a result of an analysis made by the image analysis means.