Disclosed herein is a waterproof sound-transmitting sheet, the thickness of which can easily be adjusted and which has a high sound transmitting efficiency and excellent waterproofness, and a method for producing same. The waterproof sound-transmitting sheet, which is attached to a sound hole of a case, includes: a support layer made of a film-shaped porous material and formed in the case; and a waterproofing layer formed on one side of the support layer in the shape of a porous nanoweb in which fine fiber strands are crosswisely layered and exposed to the outside of the case.