A microscope for total internal reflection microscopy. The microscope includes at least one light source configured to provide an illumination light to an illumination beam path for an evanescent illumination of a specimen so as to reflect the illumination light at an interface to the specimen or a specimen cover so as to return reflection light into the illumination beam path, an objective through which the illumination light and detection light are directable, a detection device, and a coupling device. The coupling device includes a mirror disposed in the illumination beam path. The mirror has a reflecting surface and a hole, the hole being configured to pass the illumination light there through so as to couple the illumination light into the illumination beam path. The reflecting surface is configured to couple out at least a part of the reflection light and to direct the coupled-out reflection light to the detection devices so as to enable determination from a beam path of the coupled-out reflection light, at least one of a quantifiable parameter and a qualifiable parameter of at least one of the evanescent illumination and an evanescent field created in the specimen.