0_2706 Over the past decades, advancements in electron microscopy have been driven by the aim of reaching atomic-scale resolution, thanks to the development of methods able to correct the spherical aberrations of the microscope lenses. Such Cs-correction techniques are based on multipole lens systems enabling resolution at the sub-Angstrom scale. Here, we propose an alternative approach to correct spherical aberrations in ultrafast electron microscopes based on a laser-induced plasma, which is able to dynamically shape the transverse profile of a pulsed electron beam. This approach is extremely versatile and does not require complex hardware modifications to the TEM.When a high-intensity infrared laser pulse is focused onto a metallic structure, electrons are emitted from the metal forming a negative charge cloud that dynamically evolves in space and time, producing a time-dependent electric field that interacts with the electron beam. The spatial configuration of the electric field depends on the metallic structure geometry and the time delay from plasma formation. By tailoring these parameters, the plasma can act as a lens with a negative spherical aberration coefficient (Cs) that compensates the intrinsic positive aberration of the microscope lenses. First, we have developed a numerical code to solve Poisson’s equation with given boundary conditions, enabling the computation of the electric field for various plasma configurations and the estimation of their effect on an electron beam. From the simulations, we demonstrate that a toroidal charge distribution can act as an effective lens for the electron beam introducing a negative Cs. Then, we have performed experiments in the UTEM by generating plasma from micrometer-sized holes obtained into gold disks via laser machining. Such structures, which are installed within the column of the UTEM before the sample plane, are able to create a toroidal charge cloud following IR laser irradiation. We investigated structures with different diameters and adopted a variable laser fluence. Experimental results agree well with the simulated dependence of the absolute value of Cs on both laser fluence and charge distribution diameter. Moreover our measurements confirm that, for specific time delays, the measured Cs coefficient assumes negative values.These findings suggest that light-induced plasma may offer a viable approach for correcting spherical aberrations in electron microscopy. Future research will focus on optimizing laser power and sample geometry to achieve the plasma configuration that enables exact aberration correction in the TEM, opening new possibilities for high-resolution electron microscopy.