In the present study, muscle activity was measured after transcranial magnetic stimulation (TMS) was applied over the primary motor cortex during finger tapping. The duration of finger tapping was increased by the application of TMS. A remarkable change in electromyogram (EMG) of hand muscles was also observed during and after finger tapping. The silent period, in which voluntary EMG during the finger tapping was suppressed by TMS, was observed. Integral EMG revealed that TMS increased muscle activity at the completion of the finger tap after silent period. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.