A pressure-sensitive adhesive sheet 1 for an optical data recording medium D1 from which a signal with a mark length shorter than the resolution limit of an optical system of a reproducing device is capable of being reproduced by reproduction light emitted during reproducing, the pressure-sensitive adhesive sheet 1 having an adhesive transparent resin layer 11 to be disposed on an data recording layer 3 of the optical data recording medium D1, the transparent resin layer 11 having a (meth)acrylate copolymer containing no acidic group as a main component, the transparent resin layer 11 having a storage elastic modulus at 23° C. of 1.5×105 Pa or less and a gel fraction of 68 wt % or more. The transparent resin layer 11 of this pressure-sensitive adhesive sheet 1 for an optical data recording medium can be used for producing an optical data recording medium which can reproduce from a mark with a length shorter than the resolution of an optical system of a reproducing device, and which is stable against changes in the external environment when responding to status of use.