A fan blade includes a hub and a plurality of vanes. The vanes are connected to the hub. Each of the vanes includes a main body and a guide plate. The main body has an inflow surface and an outflow surface. The guide plate is disposed on the outflow surface. When the fan blade rotates, an airflow occurs and flows into a side of the fan blade via the inflow surface, and the guide plate guides part of the airflow to flow out of another side of the fan blade in a first direction and a second direction so as to cool an electronic component disposed adjacent to the another side of the fan blade.