Functionally integrated laser scanning microscope formed for scanning a sample by means of a laser illumination selectively in a confocal, line or widefield operating mode with point-, line- or field-shaped illumination of the sample or of a sample region comprising - a laser light source, an illumination and detection beam path, a detection apparatus and at least one objective, each formed for use in each selectable operating mode, wherein - the illumination and detection beam path comprise optical means for configuring the laser illumination, at least one scanner for scanning the sample by means of the laser illumination, and a beam splitter for splitting illumination and detection light, characterized in that - for each of the selectable operating modes, the detection beam path ends at the same image sensor of the detection apparatus, - controllable optical elements are arranged in the detection beam path, wherein one of the controllable optical elements is formed as a switch element for changing the beam guidance by means of incoupling the detection radiation into different detection paths in dependence on the respective selected operating mode, wherein a respective detection path is fixedly assigned to each operating mode, and - in a first detection path, the detection radiation is passed through and influenced by at least one optical assembly arranged as fixed in position in the beam path, - in a second detection path, the detection radiation is redirected around this optical assembly, - wherein the first detection path is assigned to the confocal operating mode and the second detection path is assigned to the line or widefield operating mode, - whereby an image plane in which a pinhole is arranged is formed at a defined position in the first detection path and a pupil plane is formed in the second detection path at the location of the image plane. - a laser light source, an illumination and detection beam path, a detection apparatus and at least one objective, each formed for use in each selectable operating mode, wherein - the illumination and detection beam path comprise optical means for configuring the laser illumination, at least one scanner for scanning the sample by means of the laser illumination, and a beam splitter for splitting illumination and detection light, characterized in that - for each of the selectable operating modes, the detection beam path ends at the same image sensor of the detection apparatus, - controllable optical elements are arranged in the detection beam path, wherein one of the controllable optical elements is formed as a switch element for changing the beam guidance by means of incoupling the detection radiation into different detection paths in dependence on the respective selected operating mode, wherein a respective detection path is fixedly assigned to each operating mode, and - in a first detection path, the detection radiation is passed through and influenced by at least one optical assembly arranged as fixed in position in the beam path, - in a second detection path, the detection radiation is redirected around this optical assembly, - wherein the first detection path is assigned to the confocal operating mode and the second detection path is assigned to the line or widefield operating mode, - whereby an image plane in which a pinhole is arranged is formed at a defined position in the first detection path and a pupil plane is formed in the second detection path at the location of the image plane.