Laser-induced vibrations and elastic stability of a clamped-clamped beam electrostatic transducer are considered under ultrafast laser pulse. It is assumed that laser pulse acts as volume heat generation with Gaussian time-profile localized in near-surface layer of the beam. Temperature load non-stationarity and non-homogeneity through length and thickness lead to appearance of thermal-induced mechanical moment and axial forced acting on the beam, which can result in buckling phenomena. Semi-analytical methods for solution of nonlinear boundary-value problems are used for static equilibrium determination of the beam in the electric field of one stationary electrode. Analytical solution of non-stationary temperature problem in the beam volume is obtained. Finally, areas in parameter space of system geometrical and mechanical properties along with laser pulse characteristics are determined which correspond to elastic stability of initial equilibrium form of the beam subjected to laser pulse.