This study focuses on the initial stages of iron surface oxidation, studied by confocal scanning laser microscopy. Pure iron cubes were prepared and polished for in situ observation. Samples were oxidized for 2–60 s by dry air at 1150 °C. A dynamic oxidation process was observed, with two reaction fronts that moved from the sample edge to the center at around 20–30- and around 40–50-s oxidation, respectively. Scanning electron microscopy (SEM) was used to characterize the iron oxide surface morphology. Pyramidal features appeared first on the surface, and then the surface became flatter with time. X-ray diffraction was used to characterize the phases of the outermost oxide layer. Overall, the content of wustite decreased and hematite content increased with oxidation time. SEM with a backscattered electron detector was used to measure the oxide layer thicknesses, and it was found that the oxide thickness increased parabolically with time. The different oxide layers within the scale were identified by an optical microscope with a polarized light source. Even after 2-s oxidation, an obvious magnetite layer was found on the wustite layer, and after 10-s oxidation, an obvious hematite layer was observed on the magnetite layer. A thicker hematite layer was observed at the sample edge. The reasons for the morphology changes are discussed.