Apparatus for detecting and characterizing particles in liquids of any kind of the order of nanometres, comprising a cell having a cell wall, wherein the liquid is situated in the cell as a suspension, wherein the cell wall has a rectangular cross section, and wherein the cell wall rests on a transverse face on a stand base, an irradiation device which irradiates the cell wall on the transverse face which faces the transverse face forming the support of the cell wall through an optical glass window in the centre, an observation device (6, 6a) which observes at a right angle to the optical axis of the irradiation device through a further optical glass window, and a control device which moves the common focus of the irradiation device and the focus of the observation device in a motorized manner across the spatial interior of the cell wall to any point, wherein the face of the cell wall which faces the optical glass window through which the irradiation device irradiates has a further optical glass window in the centre, characterized by a) a vibration damper which positions the stand base in a defined manner, b) a nanocarbon layer which covers from the outside a coextensive face of the cell wall which faces the optical glass window through which the irradiation device irradiates, c) two thermistors which monitor the temperature of the face of the cell wall in which there is situated the optical glass window through which the optical axis of the observation device runs, wherein the cell wall consists of black glass having optical windows sintered therein and is covered by an L-shaped heating and cooling element on a longitudinal face and the adjoining transverse face forming the support of the cell wall, d) two electrodes which each provide one of the two end faces of the cuboid cell wall with an electrical voltage source, wherein each of said electrodes consists of an outer electrode and an associated inner electrode, and e) an arrangement which is provided in the optical axis of the observation device and allows the switching of various filters in the beam path. a cell having a cell wall, wherein the liquid is situated in the cell as a suspension, wherein the cell wall has a rectangular cross section, and wherein the cell wall rests on a transverse face on a stand base, an irradiation device which irradiates the cell wall on the transverse face which faces the transverse face forming the support of the cell wall through an optical glass window in the centre, an observation device (6, 6a) which observes at a right angle to the optical axis of the irradiation device through a further optical glass window, and a control device which moves the common focus of the irradiation device and the focus of the observation device in a motorized manner across the spatial interior of the cell wall to any point, wherein the face of the cell wall which faces the optical glass window through which the irradiation device irradiates has a further optical glass window in the centre, characterized by a) a vibration damper which positions the stand base in a defined manner, b) a nanocarbon layer which covers from the outside a coextensive face of the cell wall which faces the optical glass window through which the irradiation device irradiates, c) two thermistors which monitor the temperature of the face of the cell wall in which there is situated the optical glass window through which the optical axis of the observation device runs, wherein the cell wall consists of black glass having optical windows sintered therein and is covered by an L-shaped heating and cooling element on a longitudinal face and the adjoining transverse face forming the support of the cell wall, d) two electrodes which each provide one of the two end faces of the cuboid cell wall with an electrical voltage source, wherein each of said electrodes consists of an outer electrode and an associated inner electrode, and e) an arrangement which is provided in the optical axis of the observation device and allows the switching of various filters in the beam path. a) a vibration damper which positions the stand base in a defined manner, b) a nanocarbon layer which covers from the outside a coextensive face of the cell wall which faces the optical glass window through which the irradiation device irradiates, c) two thermistors which monitor the temperature of the face of the cell wall in which there is situated the optical glass window through which the optical axis of the observation device runs, wherein the cell wall consists of black glass having optical windows sintered therein and is covered by an L-shaped heating and cooling element on a longitudinal face and the adjoining transverse face forming the support of the cell wall, d) two electrodes which each provide one of the two end faces of the cuboid cell wall with an electrical voltage source, wherein each of said electrodes consists of an outer electrode and an associated inner electrode, and e) an arrangement which is provided in the optical axis of the observation device and allows the switching of various filters in the beam path.