A heat dissipating device includes an electric member, a heat sink having a base to be secured on the electric member. The base includes an upper surface and includes four corner areas, and includes four posts extended upwardly from the four corner areas thereof respectively. A fan device is disposed on and secured to the posts. The heat sink includes a number of rods extended upwardly from the upper surface of the base, and each of the rods includes an upper portion, and a recess formed in the upper portions of the rods. Each of the rods preferably includes a planar surface formed on the upper portion to form the recess on top of the rods.