A light microscope, comprising: a scan illumination unit configured to illuminate a specimen with a line focus produced from an illumination light beam and moved transversely to a light propagation direction, and a descanned detection unit configured to produce a stationary first line image of the target region from detection light that originates from a target region of the specimen illuminated with the moving line focus, wherein the scan illumination unit and the descanned detection unit have a common objective which is configured to receive both the illumination light beam and the detection light, wherein the descanned detection unit includes a dispersive element which is configured to spectrally split the detection light in order to generate multiple second line images (42r, 42g, 42b) of different spectral composition, which second line images correspond to the first line image, wherein the descanned detection unit includes at least one light blocking element (64, 80, 82, 84) which blocks spectral components of the detection light that are within the wavelength range of the illumination light beam, and the scan illumination unit and the descanned detection unit have a common light deflecting element which is rotatable about two axes (x, y) lying perpendicular to each other for scanning the illumination light beam and for descanning the detection light, characterized in that the light deflecting element is a 2D scanning mirror which is arranged in a plane conjugated with respect to the rear focal plane of the objective, and the at least one light blocking element (80, 82, 84) is arranged downstream of the dispersive element and is displaceable in the splitting direction of the dispersive element. a scan illumination unit configured to illuminate a specimen with a line focus produced from an illumination light beam and moved transversely to a light propagation direction, and a descanned detection unit configured to produce a stationary first line image of the target region from detection light that originates from a target region of the specimen illuminated with the moving line focus, wherein the scan illumination unit and the descanned detection unit have a common objective which is configured to receive both the illumination light beam and the detection light, wherein the descanned detection unit includes a dispersive element which is configured to spectrally split the detection light in order to generate multiple second line images (42r, 42g, 42b) of different spectral composition, which second line images correspond to the first line image, wherein the descanned detection unit includes at least one light blocking element (64, 80, 82, 84) which blocks spectral components of the detection light that are within the wavelength range of the illumination light beam, and the scan illumination unit and the descanned detection unit have a common light deflecting element which is rotatable about two axes (x, y) lying perpendicular to each other for scanning the illumination light beam and for descanning the detection light, characterized in that the light deflecting element is a 2D scanning mirror which is arranged in a plane conjugated with respect to the rear focal plane of the objective, and the at least one light blocking element (80, 82, 84) is arranged downstream of the dispersive element and is displaceable in the splitting direction of the dispersive element.