A method of optoperforation of the membrane of a cell by application of laser pulses characterized by focusing the pulsed laser beam onto the cell membrane to be perforated, applying a series of laser pulses of predetermined pulse energy, measuring the oscillation time of the bubbles formed in the laser focus from the change in laser intensity of a test laser beam transmitted through the laser focus and caused by the bubbles in the laser focus, and increasing the pulse energy to a level at which the oscillation time of the bubbles attains a predetermined value.