We report on an InGaN-based light-emitting diode (LED) with a top p-GaN surface microroughened using the metal clusters as a wet etching mask. The light-output power for a LED chip with microroughening was increased compared to that for a LED chip without one. This indicates that the scattering of photons emitted in the active layer was much enhanced at the microroughened top p-GaN surface of a LED due to the angular randomization of photons inside the LED structure, resulting in an increase in the probability of escaping from the LED structure. By employing the top surface microroughened in a LED structure, the power conversion efficiency was increased by 62%.