end of the resilient contact piece. [0034]FIGS. 7A and 7B are a plan view and a side view showing another example of a resilient contact piece having projections on both sides of the distal end of the resilient contact piece. [0035]FIGS. 8A and 8B a plan view showing the shape of a probe unit and a perspective view illustrating how the probe unit is used. [0036]FIGS. 9A, 9B and 9C are cross secti