Abstract: An automatic analyzer which can remove air bubbles in a photometric light path within a reaction tank and can provide accurate measurement results with stability. The automatic analyzer comprises a reaction cell for mixing a sample and a reagent therein, a constant temperature bath for holding water in which the reaction cell is immersed, a suction pipe for sucking the water in the constant temperature bath, a return pipe for returning the water to the constant temperature bath, a pump disposed between the suction pipe and the return pipe and circulating the water, a heater for heating the water circulated in the constant temperature bath by the pump, and an air-bubble removing unit disposed between the suction pipe and the return pipe, having a water-tight structure to hold the constant temperature bath water therein, and removing air bubbles based on a difference in gravity between the water and the air bubbles.

Abstract: The invention provides a sample observation method capable of understanding the three-dimensional shape of a sample in a wider range. The observation method of the invention calculates heights (height differences) in the whole domain of an image, from plural sheets of images of different field-of-view angles, being in focus over the whole image, attained by means of the focal depth expanding function to thereby create a map (Z map) of the height information by each pixel, and displays a three-dimensional image as a bird's-eye view. The method also displays to superpose a Z map attained from image signals reflecting the surface structure on a Z map attained from image signals reflecting the composition information with different colors, which makes it possible to clearly understand the spatial distribution of a substance of unique composition inside the sample.