  We present the first observations of large amplitude waves in a well-defined
electron diffusion region at the sub-solar magnetopause using data from one
THEMIS satellite. These waves identified as whistler mode waves, electrostatic
solitary waves, lower hybrid waves and electrostatic electron cyclotron waves,
are observed in the same 12-sec waveform capture and in association with
signatures of active magnetic reconnection. The large amplitude waves in the
electron diffusion region are coincident with abrupt increases in electron
parallel temperature suggesting strong wave heating. The whistler mode waves
which are at the electron scale and enable us to probe electron dynamics in the
diffusion region were analyzed in detail. The energetic electrons (~30 keV)
within the electron diffusion region have anisotropic distributions with
T_{e\perp}/T_{e\parallel}>1 that may provide the free energy for the whistler
mode waves. The energetic anisotropic electrons may be produced during the
reconnection process. The whistler mode waves propagate away from the center of
the 'X-line' along magnetic field lines, suggesting that the electron diffusion
region is a possible source region of the whistler mode waves.
