A composite synthesis method and apparatus, a vaporizer for the composite synthesis apparatus, a vaporizer heater and a composite. In the composite synthesis apparatus using simultaneous vaporization, two or more vaporizers are heated by heaters such that samples vaporized by the vaporizers are supplied into a reactor to synthesize a composite. The apparatus and method may prepare multiple-metal or metal-carbon heterogeneous composites, and may be applied to various metal- and carbon-based adsorbents, absorbents, gas/liquid separation membranes and various catalyst processes. Further, the composite may be applied to various industrial fields through change in metal components or carbon structures.