To meet the growing demands for energy saving, ejectors are increasingly being considered in refrigeration cycles. The two-phase internal flow of these ejectors, which has slower sound velocity than the single gas phase, easily becomes supersonic and generates a shock wave. As this shock wave greatly contributes to the pressure increase in the ejector, elucidating its characteristics is essential for increasing the efficiency of the ejector. In this study, we experimentally visualized the internal flow in a two-dimensional ejector using hot-water as coolant and observed the form changes in the two-dimensional shock wave occurring in the nozzle. We also measured the speed changes in the two-phase flow induced by the shock wave. The experimental results showed that, within the area of its formation, the shock wave altered from oblique to near-normal. Furthermore, the temporal changes in luminance distribution were captured in a video and those in the droplet velocity were measured using a luminance cross-correlation method. The droplet velocity behind the shock waves of two-phase flow found to decease gently. And this phenomenon is characteristic for the shock wave of two-phase flow.