An immersion microscope objective includes, a first lens group, a second lens group, and a third lens group, wherein the first lens group has a positive refractive power and includes a first cemented lens disposed nearest to the object side in the first lens group, the second lens group includes a second cemented lens, the third lens group includes a lens component that has a positive refractive power and changes a divergent light beam incident from the second lens group to a convergent light beam, two lens components that change the convergent light beam to a divergent light beam, and a lens component that has a positive refractive power and changes the divergent light beam to a parallel light beam and emits the parallel light beam, and the following conditional expressions (1) is satisfied: 60 mm2≦d0×f×NAo≦500 mm2  (1).