A vapor chamber structure is provided. The vapor chamber structure comprises a first plate, a second plate, and at least one capillary foil. The first plate comprises a first inner surface where a first recessed part with a depth is formed, a first flow reservoir formed cyclicly at an edge of the first inner surface, and plurality of expanding flow channels formed between the first flow reservoir and the first recessed part. The second plate comprises a second inner surface where a second recessed part with a depth is formed, a second flow reservoir formed as a loop at a edge of the second inner surface, and plurality of reducing flow channels formed between the second flow reservoir and the second recessed part. Plurality of expanding flow channels and plurality of reducing flow channels can accelerate flowing speed of a working fluid in the vapor chamber structure so that heat circulating and transferring efficiency is improved. |