We present a simulated NGST deep observation of a blank field. The simulation shows that the NGST will be able to detect about 104 objects at very high redshifts (z>5) in a single field with a long exposure time (10 hours) per broadband filter. Precise redshifts of such objects could be obtained using low resolution spectroscopy for objects with KAB < 28-29 or z< 15.