We report a type-II GaSb-based interband cascade laser operating a continuous wave at room temperature. The cas-cade region of interband cascade laser was designed using the’W’ configuration of the active quantum wells and the’Carrier Rebalancing’ method in the electron injector. The devices were processed into narrow ridges and mounted epitaxial side down on a copper heat sink. The 25-μm-wide, 3-mm-long ridge without coated facets generated 41.4 mW of continuous wave output power at T=15?C. And a low threshold current density of 267 A/cm2 is achieved. The emission wavelength of the ICL is 3452.3 nm at 0.5 A.