A vapor chamber device includes a first casing, a first capillary structure and a second casing. The first casing includes a first plate portion, first protrusions and a first side wall. The first capillary structure is disposed over an inner bottom surface of the first plate portion and surrounds the first protrusions. The second casing is stacked on the first casing, and the second casing includes a second plate portion, second protrusions and a second side wall. The first side wall is connected to the second side wall, and steam passages are formed between the second protrusions. The second plate portion includes connecting areas for the second protrusions, and the first protrusions are connected to the connecting areas. These second protrusions press against the first capillary structure. |