A combustor device of a gas turbine engine, which combustor device is supplied with compressed air from a compressor and delivers combustion gas to a turbine, comprises an outer casing and an inner casing defining therein a combustion chamber and forming between the outer and inner casings an annular passage for the intake of the compressed air, a swirler opening being provided at the innermost end of the inner casing for taking the compressed air into the combustion chamber. Swirling motion of the compressed air around the inlet of the swirler opening, which causes static pressure drop at the swirler opening inlet and resultant undesirable combustion, is effectively prevented by providing swirl preventing vanes between the inner and outer casings. When the swirl preventing vanes are provided near the swirler opening, guide vanes may be provided near the upstream end of the annular passage to intentionally impart swirling motion to the compressed air to prevent non-uniform distribution of the supplied compressed air.