An impingement cooling structure is provided. The impingement cooling structure includes a flow channel formed between a first wall and a second wall facing the first wall, a plurality of impingement cooling holes disposed in the first wall such that the plurality of impingement cooling holes are spaced apart from each other along the flow channel, and a flow diverter convexly protruding from a surface of the second wall in each space between injection axes of the plurality of impingement cooling holes.