Abstract: An automatic opening device for the window of a radiographic cassette including a fixed bracket (1); motor-driven equipment (8) sliding along the bracket (1) between a position of engagement with the window and a position of full opening of the window, including a cap element (12) sliding vertically between positions of engagement and disengagement with the window and equipped with a spring (15) which is compressed when the cap element (12) is in the disengagement position as to the window, at least one movable side (10) sliding on the fixed brakcet (1), and trailing with it the cap element (12), and a wedge element (11) causing the cap element (12) to move vertically.