The invention relates to a method for determining a spatial position of a liquid jet (1), in particular of a liquid jet (1) for optically guiding a laser beam, the method comprising the following steps: providing a collision object (2) having a measuring point for interacting with the liquid jet (1); detecting a state of the liquid jet (1) in a first configuration between the collision object (2) and the liquid jet (1); changing the configuration such that the state of the liquid jet (1) changes; and detecting the configuration change between the first and second configurations.