Abstract: The subject of the invention is a spectroscopic analysis device comprising a light source, a light analyzer comprising an entrance slit, a diffraction grating and at least one exit slit which are disposed along a Rowland circle, and an optical transmission system.According to the invention, the entrance slit (3) is mounted so as to be displaceable along the Rowland circle (1), on either side of a central position, the optical transmission system comprises a first, fixed part (I) associated with the light source (5; 8) and a second, movable part (II) associated with the entrance slit (3) and mounted so as to be displaceable parallel to itself in a direction (a.sub.1, a.sub.2 ; b.sub.1, b.sub.2 ; c.sub.1, c.sub.