The first c.w. operation of a GaInAsP/InP stripe laser (λ≃1.3 μm) having a chemically etched mirror has been achieved at room temperature. One of the cavity facets was monolithically formed by a wet chemical etch and passivated with a Si3N4 film to simplify bonding the chip on a heat sink. Threshold currents for 10 μm-stripe lasers were as low as 190 mA and the differential quantum efficiencies from the cleaved facet were ~18% (27°C, pulsed). C.W. operation was obtained up to 35°C.