A heat dissipating fan comprising: a housing including a base and a sidewall coupled to the base, with the sidewal defining a compartment, with the housing further including an air inlet and an air outlet, with the air inlet and the air outlet being in communication with the compartment; a stator coupled to the base of the housing; an impeller rotatably coupled to the stator; and a control element including a driving circuit electrically connected to the stator for driving the impeller to rotate, characterized in that: the housing further includes a dust channel communicating the compartment with an outside, the control element further includes a rotating direction control circuit electrically connected to the driving circuit, wherein when the rotating direction control circuit controls the impeller to rotate in a first direction, ambient air currents are drawn in via the air inlet and pass through the air outlet to a heat source for dissipating heat, and wherein when the rotating direction control circuit controls the impeller to rotate in a second direction reverse to the first direction, ambient air currents are drawn in via the air inlet and then exit the housing via the dust channel to dispel dust accumulated inside the housing. a housing including a base and a sidewall coupled to the base, with the sidewal defining a compartment, with the housing further including an air inlet and an air outlet, with the air inlet and the air outlet being in communication with the compartment; a stator coupled to the base of the housing; an impeller rotatably coupled to the stator; and a control element including a driving circuit electrically connected to the stator for driving the impeller to rotate, characterized in that: the housing further includes a dust channel communicating the compartment with an outside, the control element further includes a rotating direction control circuit electrically connected to the driving circuit, wherein when the rotating direction control circuit controls the impeller to rotate in a first direction, ambient air currents are drawn in via the air inlet and pass through the air outlet to a heat source for dissipating heat, and wherein when the rotating direction control circuit controls the impeller to rotate in a second direction reverse to the first direction, ambient air currents are drawn in via the air inlet and then exit the housing via the dust channel to dispel dust accumulated inside the housing. the housing further includes a dust channel communicating the compartment with an outside, the control element further includes a rotating direction control circuit electrically connected to the driving circuit, wherein when the rotating direction control circuit controls the impeller to rotate in a first direction, ambient air currents are drawn in via the air inlet and pass through the air outlet to a heat source for dissipating heat, and wherein when the rotating direction control circuit controls the impeller to rotate in a second direction reverse to the first direction, ambient air currents are drawn in via the air inlet and then exit the housing via the dust channel to dispel dust accumulated inside the housing.