An electronic apparatus includes a PCB with a heat generating electronic component disposed thereon, a heat sink, and a mounting device for mounting the heat sink onto the heat generating electronic component. The mounting device includes a mounting frame and a wire clip. The mounting frame surrounds the heat sink, and includes two first mounting arms and two second mounting arms disposed above the first mounting arms. The first mounting arms abut on the PCB. A pair of engaging wings are formed on the second mounting arms. The wire clip includes a pivot axle pivotably attached to the mounting frame and two resilient arms at opposite sides of the mounting frame. The resilient arms abut against the heat sink and engage with the engaging wings, thereby exerting a resilient force on the heat sink toward the heat generating electronic component.