Method for Checking and/or Calibrating a Horizontal Axis of a Rotating Laser

A method for checking and/or calibrating a horizontal axis of a rotating laser using a laser receiver and a controller device which is communicatively connected to the rotating laser and the laser receiver where the rotating laser emits a laser beam rotating about an axis of rotation in a laser plane. An inclination angle is ascertained using a first fitting function and a second fitting function where the inclination angle is used for the checking and/or the calibrating of the horizontal axis.