Immersion microscope objective

An immersion microscope objective comprising:

• a first lens group that consists of a first cemented lens and that has a positive refractive power, the first cemented lens consisting of a planoconvex lens having a plane surface facing an object and a first meniscus lens having a concave surface facing the object, and the first meniscus lens having a thickness on an optical axis that is greater than a radius of curvature of a lens surface of an image side of the first meniscus lens;
• a second lens group that has a positive refractive power, the second lens group including a first single lens that is a biconvex lens having a positive refractive power, a second single lens that is a biconvex lens, and a plurality of second cemented lenses;
• a third lens group that consists of a third cemented lens with a meniscus shape that has a concave surface facing an image;
• and
• a fourth lens group that has a negative refractive power and that includes a third single lens that is a biconcave lens and a fourth cemented lens consisting of a plurality of meniscus lenses, each of the plurality of meniscus lenses having a concave surface facing the object,
• wherein:
• the object, the first lens group, the second lens group, the third lens group, and the fourth lens group are arranged in this order,
• the second lens group consists of, in order from an object side to an image side, the first single lens, the second single lens, a first cemented triplet lens, a second cemented triplet lens, and a cemented doublet lens, and
• the immersion microscope objective satisfies the following conditional expression:
• 2≤h1/h2≤4 (1)
• where h1 indicates a height of an axial marginal ray at a lens surface that is closest to the object among lens surfaces of the third cemented lens, and h2 indicates a height of an axial marginal ray at a lens surface that is closest to the image among the lens surfaces of the third cemented lens.