A heat-dissipating net structure disposed in a vapor chamber unit includes latitudinal strand units and longitudinal strand units crossing each other. Each latitudinal strand unit has a single latitudinal strand extending in a first direction. Each longitudinal strand unit has at least two longitudinal strands extending in a second direction different from the first direction, with the longitudinal strands passing over and under the latitudinal strand units and twisting densely in the second direction to form a plurality of crossing points between the longitudinal strands because of the twisting arrangement. The twisting arrangement of the longitudinal strands prevents unnecessary spaces formed between any two adjacent longitudinal strand units, improves the capillary phenomenon of working fluid within the vapor chamber unit, and facilitates the phase transition of the working fluid, thereby attaining the effect of dissipating heat quickly.