A new high speed switch module was constructed using a high temperature superconducting bulk core (YBa2Cu3O7-x or Bi2Sr2CaCu2O8) in the liquid nitrogen and two switching transistors having maximum rate of 1 A. The main part of the module is the Royer oscillator type magnetic multivibrator. The multivibrator starts to oscillate by applying a ON signal pulse current (ION) to a coil set around the core, and stops oscillation by applying a OFF signal pulse current (IOFF) to a small transistor which shorts another coil of the core. This module switched with the turn-on time tON of about 0.2µs and the turn-off time tOFF of about 0.2µs when two switching transistors having a maximum rate of 1 A used. The values of tON and tOFF is about 1/10 and 1/100 (due to the Meissner effect or zero inductance effect) that of the multivibrator transistor module using an amorphous ferromagnetic core. These transistor switch modules are applicable to construct high-speed inverters for the control of the small motors having high rotation speed.