  Three dimensional electrodynamic trapping of neutral atoms has been
demonstrated. By applying time-varying inhomogeneous electric fields with
micron-sized electrodes, nearly $10^2$ strontium atoms in the $^1S_0$ state
have been trapped with a lifetime of 80 ms. In order to design the electrodes,
we numerically analyzed the electric field and simulated atomic trajectories in
the trap, which showed reasonable agreement with the experiment.
