Method for reprogramming living cells in which a cocktail comprising at least three transcription factors is transfected into the interior of at least one cell in order to convert this cell into an iPS cell or another type of cell, comprising the following steps: - providing a cocktail without viral carrier with at least three transcription factors commonly used for direct reprogramming in an aqueous environment of the at least one cell to be reprogrammed, - providing a radiation source in the form of a femtosecond laser with a pulse repetition frequency ranging between 50 MHz and 2 GHz with a wavelength ranging from 700 to 1200 nm, - directing a laser beam of the femtosecond laser by means of a laser-scanning microscope with a numerical aperture of between 0.9 and 1.5 on a cell membrane of the cell to be programmed in a focus in a sample with the at least one cell on a displaceable x-y table , - directing an attenuated, non-destructive laser beam of the femtosecond laser , which is also used for optical treatment, for establishing and observing the at least one selected cell in the focus of the laser-scanning microscope by means of a scanner , and - controlling the position of the at least one cell with respect to the focus, the exposure period and laser output for the optical treatment such that the focus depending on the pulse repetition frequency with an output between 7 and 100 mW generates a transient small-pore opening with a size in the range of up to 500 nm within a cell membrane of the cell in order to allow a diffusion of the cocktail for multiple reprogramming of the cell through the cell membrane into the interior of the cell such that a virus-free optical multiple reprogramming takes place. - providing a cocktail without viral carrier with at least three transcription factors commonly used for direct reprogramming in an aqueous environment of the at least one cell to be reprogrammed, - providing a radiation source in the form of a femtosecond laser with a pulse repetition frequency ranging between 50 MHz and 2 GHz with a wavelength ranging from 700 to 1200 nm, - directing a laser beam of the femtosecond laser by means of a laser-scanning microscope with a numerical aperture of between 0.9 and 1.5 on a cell membrane of the cell to be programmed in a focus in a sample with the at least one cell on a displaceable x-y table , - directing an attenuated, non-destructive laser beam of the femtosecond laser , which is also used for optical treatment, for establishing and observing the at least one selected cell in the focus of the laser-scanning microscope by means of a scanner , and - controlling the position of the at least one cell with respect to the focus, the exposure period and laser output for the optical treatment such that the focus depending on the pulse repetition frequency with an output between 7 and 100 mW generates a transient small-pore opening with a size in the range of up to 500 nm within a cell membrane of the cell in order to allow a diffusion of the cocktail for multiple reprogramming of the cell through the cell membrane into the interior of the cell such that a virus-free optical multiple reprogramming takes place. <EOS>