An electronic device includes a bottom plate, a circuit board having an electronic component, a fan, and an airflow guide member. The circuit board is fixed to the bottom plate. The fan is arranged at the front of the circuit board. The airflow guide member is arranged between the fan and the circuit board. The airflow guide member includes an airflow guide wall defining a number of spaced slots, and a number of stop plates selectively inserted into the corresponding slots of the airflow guide wall, to leave some of the slots directly in front of the bottom of the electronic component open.