One to ten Fe monatomic layers (ML) with wedge-shape were deposited on the NiO(001) substrate by molecular beam epitaxy (MBE) and pulsed laser deposition (PLD), respectively. The analysis in situ of surface magneto-optic Kerr effect indicates that the Fe layer gives rise to an about 2ML thick magnetic dead layer at the interface of Fe/NiO by MBE deposition. The magnetic dead layer is about 3ML for the method of PLD. X-ray photoelectron spectroscopy indicates that both ways of deposition can lead to interfacial chemical reactions.