In a confocal laser scanning microscope with an illuminating configuration (2), which provides an illuminating beam for illuminating a specimen region (23), with a scanning configuration (3, 4), which guides the illuminating beam over the specimen while scanning, and with a detector configuration (5), which via the scanning configuration (3, 4) images the illuminated specimen region (23) by means of a confocal aperture (26) on to at least one detector unit (28), it is provided that the illuminating configuration (2) of the scanning configuration (3, 4) provides a line-shaped illuminating beam, that the scanning configuration (3, 4) guides the line-shaped illuminating beam over the specimen f while scanning and that the confocal aperture is designed as a slit aperture (26) or as a slit-shaped region (28, 48) of the detector unit (28) acting as a confocal aperture.