Immersion lens holding device

An immersion lens supporting device for supporting an immersion lens movably in a direction perpendicular to an optical axis of an objective lens between the objective lens and a sample of an observation object, the supporting device comprising:

• an immersion lens:
• a lens holder having a lower opening and an upper opening and holding the immersion lens in a free state in which a lens bottom surface protrudes downward through the lower opening so as not to fix the immersion lens;
• and
• a lens cover which is provided for the upper opening of the lens holder so as to cover the upper opening, the lens cover being located above the immersion lens so that the immersion lens is held in a space sandwiched between the lens holder and the lens cover, wherein,
• a cover bottom surface of the lens cover on the immersion lens side is a planar surface disposed on a plane perpendicular to the optical axis, and the lens cover is configured such that, when the lens cover comes into contact with the immersion lens, the cover bottom surface comes into one-point contact with a spherical lens top surface of the immersion lens, and
• wherein
• the lens cover is provided with a positioning portion having a predetermined pattern which is capable of carrying out positioning of the immersion lens with respect to the objective lens, with reference to an image of the positioning portion of the lens cover observed via the objective lens.