A microscope objective includes at least five lens components, which are divided into three groups that are, in order from an object side: a front group having a positive refracting power as a whole and having a meniscus lens component with an object-side surface thereof being concave toward the object side; a middle group having a positive refracting power as a whole and having a plurality of cemented lens components; and a rear group having a pair of concave air-contact surfaces arranged adjacent and opposite to one another, wherein the following conditions are satisfied: 3≦D0/f≦6 and 1≦H2/H1≦1.5, where D0 is an axial distance from an object surface to a rearmost surface of the microscope objective, f is a focal length of the microscope objective, H2 is a height of a marginal ray as emergent from the rearmost surface of the microscope objective, and H1 is a maximum height of the marginal ray as passing through the front group and the middle group.