A device for multi-photon fluorescence microscopy for obtaining information from biological tissue, comprising - a laser unit for generating an excitation radiation, - an optical unit which is formed to focus the excitation radiation for generating an optical signal at different locations in or on an object to be examined, and - a detector module for detecting the optical signal from the region of the object, wherein the optical unit for generating the optical signal at different locations in or on the object is movable in at least one direction (X, Y, Z) relative to the object characterized in that - the device includes a control and processing unit and a patient module connected with the control and processing unit, which for examining the object can be placed relative to the object, wherein the optical unit is part of the patient module, - the laser unit generates an excitation radiation with a first wavelength and in the patient module a frequency doubler for halving the wavelength of the excitation radiation is connected before of the optical unit, - the patient module includes a contact portion transmissive for the excitation radiation and the optical signal, which for examining the object must be brought in contact with the object, wherein means are provided which move the optical unit in horizontal direction (X, Y) relative to the contact portion within the patient module for generation of sectional images with given edge length, - the laser unit is part of the control and processing unit, wherein an optical fiber connects the laser unit with the patient module for transmitting the excitation radiation towards the optical unit, and - the optical unit is movable independent of the optical fiber for transmitting the excitation radiation. - a laser unit for generating an excitation radiation, - an optical unit which is formed to focus the excitation radiation for generating an optical signal at different locations in or on an object to be examined, and - a detector module for detecting the optical signal from the region of the object, wherein the optical unit for generating the optical signal at different locations in or on the object is movable in at least one direction (X, Y, Z) relative to the object - the device includes a control and processing unit and a patient module connected with the control and processing unit, which for examining the object can be placed relative to the object, wherein the optical unit is part of the patient module, - the laser unit generates an excitation radiation with a first wavelength and in the patient module a frequency doubler for halving the wavelength of the excitation radiation is connected before of the optical unit, - the patient module includes a contact portion transmissive for the excitation radiation and the optical signal, which for examining the object must be brought in contact with the object, wherein means are provided which move the optical unit in horizontal direction (X, Y) relative to the contact portion within the patient module for generation of sectional images with given edge length, - the laser unit is part of the control and processing unit, wherein an optical fiber connects the laser unit with the patient module for transmitting the excitation radiation towards the optical unit, and - the optical unit is movable independent of the optical fiber for transmitting the excitation radiation.