Abstract: A laser scanning microscope (LSM) having variable light intensity and a control method for the same. The light intensity of a laser beam in an LSM has been controlled to date with high accuracy, but also high costs by means of an acousto-optic component (AOM, AOTF). According to the invention, such a component for beam modulation is to be omitted, without reducing the exposure accuracy of the sample. In an LSM, a directly modulated laser diode (10) is used with an electric control (12) for direct modulation. Said laser diode (10) has a turn-on delay of the light intensity that is dependent on the amount of the control variable when subjected to an electric control variable. The control (12) is designed such that the fluctuation width (??tV) of the occurring turn-on delay (?tV) is smaller than 1 ?s, particularly smaller than 0.5 ?s. Thus highly exact modulation without an acousto-optic component is possible.