Internal magnetic probes are used for direct measurements of time-varying magnetic fields in a heating experiment of a field-reversed configuration (FRC) plasma by applying fast rising magnetic pulse. A large amplitude oscillation is detected by magnetic probes which are oriented with their axis in the azimuthal direction. The phase velocity of the oscillation in the direction parallel to the equilibrium magnetic field approximately agrees with the Alfvén velocity. The experimental results suggest that the shear Alfvén wave is excited. The excited shear Alfvén wave may play an important role in the heating of the FRC plasma.