An impeller of a centrifugal fan includes multiple blades arranged annularly around a rotational axis, a main plate, a shroud, main plate-side welded portions between main plate-side blade axial ends of the blades and the main plate, and shroud-side welded portions between shroud-side blade axial ends of the blades and the shroud. The main plate is arranged opposite to main plate-side blade axial ends. The shroud is arranged opposite to shroud-side blade axial ends. The main plate-side welded portions have main plate-side welding holes that are recesses extending through the main plate to portions of the main plate-side blade axial ends. The shroud-side welded portions have shroud-side welding holes that are recesses extending through the shroud to portions of the shroud-side blade axial ends.