The transient switching characteristics of the metal-insulator (tunnel)-silicon thyristor under base voltage drive are examined. In the monostable common emitter mode measurements are carried out to establish the dependence of the turn-on delay and rise and fall times on base drive, pulsewidth and bias point. The turn-off delay time is also examined, and the results are explained qualitatively. The operation of the device in the monostable common collector mode and the bistable mode are also examined.