A protective device for optical and/or electronic apparatuses, in particular space telescopes, is described, wherein the device is such as to removably close an aperture, through which apparatuses may be accessed, the device being such as to achieve a first and second operating configuration, respectively, for allowing or inhibiting access to apparatuses through aperture. The device includes a supporting structure having at least one supporting beam, which is transversely positioned with respect to aperture; a plurality of covering elements comprising at least a pair of elements, which are rotatably coupled to the same supporting beam; and actuation means for rotating the covering elements between a first and second angular position, in order for the device to attain the first or second operating configuration, respectively, wherein, in the second operating configuration, the covering elements are such as to define together a screen for aperture.