A centrifugal blower device includes a rotating shaft, a turbo fan unit and a casing. A shroud ring of the turbo fan unit and a cover portion of the casing form a gap between them. The gap includes a radial gap formed between the cover portion and the shroud ring in a radial direction and an axial gap formed between the cover portion and the shroud ring in an axial direction. The radial gap is located at a position outside of a shroud-side inner peripheral end in the radial direction. The axial gap is located at a position inside of the radial direction in the radial direction. A minimum gap dimension of the radial gap is smaller than a minimum gap dimension of the axial gap. A shortest distance between the shroud-side inner peripheral end and the cover portion is larger than the minimum gap dimension of the radial gap.