A microwave oven provided with a cooking container arranged in a cooking compartment for both steaming and grilling food. The cooking container includes a main body and a lid heated by high-frequency waves, a supporting member for selectively supporting the lid so as to rest on the upper surface of the main body, a rack selectively arrangable in the main body for supporting food so as to be steamed, and first and second heating members respectively covered on an outer surface of the bottom of the main body and an upper surface of the lid for generating heat by using the high-frequency waves. An inner surface of the bottom of the main body forms a first grill plane and a lower surface of the lid forms a second grill plane so that the food is grilled by the first and second grill planes when disposed so as to contact food.