Provided is the lid of a beverage container consisting of synthetic resin similarly to the container and constituted in such a manner that a straw can easily run through the lid, and the content, i.e. the beverage, does not leak even if shock is applied. The lid of a beverage container consists entirely of synthetic resin (R), wherein a substantially circular straw sticking region (20) is provided in a part (e.g. the center) of the lid, a plurality of cuts (Hc) having a depth equal to ¼-½ of the thickness of the synthetic resin material are formed in the straw sticking region (20), and the straw sticking region (20) has a diameter of 8.0 mm or less and the cut (Hc) has a length of 3.0 mm or less.