Abstract: A device to detect holes in a continuously winding strip of material of the type formed of a vertical frame which, placed in the path of said strip of material via a horizontal slot delimiting said frame into two upper and lower bodies, each opening onto said slot via windows opened opposite one another, said upper body being intended to support a first optical sub-assembly for emission for a source of light in the direction of said strip passing below said upper body, and said lower body being intended to support a second optical sub-assembly for reception for said light emitted by said first sub-assembly and able to filter through said holes in said strip of material passing above said trip, wherein said first optical sub-assembly for emission is constituted by a stimulated emission of radiation, called laser radiation, and said optical sub-assembly for reception is constituted by photodiodes sensitive to the low luminous flux emitted by said laser radiation.