A centrifugal fan is disclosed and includes a housing, a fan wheel, a first throat portion and a second throat portion. The housing includes a lower cover connected to an upper cover through a peripheral wall to form an accommodation space and an outlet. The upper cover includes an inlet communicated with the outlet. The fan wheel is disposed on the lower cover and accommodated in the accommodation space. The fan wheel is rotated along a rotation direction. The first throat portion is disposed adjacent to a lateral end of the outlet and protrudes from the peripheral wall toward the accommodation space. The second throat portion is disposed adjacent to another lateral end of the outlet, and protrudes from the peripheral wall toward the accommodation space. When the fan wheel is rotated along the rotational direction, an airflow is guided from the first throat portion to the second throat portion.