Patent ID: 8379305

Claim:
An observation unit comprising: an observation device observing a sample, a placing table on which the sample is placed, a drive device moving the placing table to an observation position where the sample is observed by the observation device, and a casing sealing a first space extending in a vertical direction, wherein the first space and a second space are defined in the casing, the first space is located on the rear surface side of the casing, the second space and the placing table are located on the front surface side of the casing, the drive device is arranged in the first space, the observation device comprises an optical system and an imaging system, the imaging system is arranged in the first space while the optical system is arranged in the second space arranged below the placing table and sealed by the casing, a shielding member preventing heat transfer from the first space to the placing table and the second space, is interposed between the first space and the placing table, and between the first space and the second space, and a light transmission part transmitting light from the observation position downward to the optical system of the observation device is formed on an upper surface wall of the casing, the upper surface wall forming a to part of the second space.