A food heating device includes a placement unit and a heating unit. The placement unit includes a housing and a placement board, wherein the placement board is disposed in the housing and is for placing a food item. The heating unit includes a water injection element and a microwave element, wherein the water injection element connects to the housing and is communication with an internal space of the housing, and the microwave element connects to the housing. The microwave element is for heating by microwave the water injected into the internal space of the housing through the water injection element and producing steam therefrom.