STEAM COOKING APPLIANCE

Provided is a steam cooking appliance. The steam cooking appliance includes a main body having a cavity that provides a cooking space in which a food is accommodated, a backguard extending upward from an upper portion of the main body, a water tank separately mounted on the backguard, a steam supply unit disposed outside the cavity to generate steam, thereby supplying the steam into the cooking space, and a water supply tube to supply water within the water tank into the steam supply unit.