The present invention effects a reduction in production cost and increases yield of a transparent resin molded article and prevents the generation of defects such as bubbles, weld lines, and sink marks. This injection molding device (2A) for a transparent resin molded article is equipped with: a die (3) for injection molding the transparent resin molded article; and a gate (5) that is provided to the peripheral edge of the die (3) and that is the inlet through which a resin material (R) is injected into the die (3). The thickness dimensions (Ta) of the die (3) are in the range of 15-25 mm, and the ratio of the diameter dimensions (D) of the gate (5) to the thickness dimensions (Ta) of the die (3) is set in the range of 1:6 to 1:3.