We present results of an optical tri-dimensional observation of the central 2′ × 12″ region of the starburst galaxy NGC 2782. The circumnuclear Hα emission lines consist of broad (δv ~ 300 km s−1), blue-shifted component and narrow (δv < 100 km s−1) component and we first revealed the two-dimensional spatial distribution of those two components. The broad Hα emitting region is extended to 6″ (> 1 kpc) south from the nucleus and the emission-line ratios indicates that shock heating may be the main excitation mechanism of the ionized gas in the region. We conclude that this region is a superbubble outflowing from the nuclear starburst region.