A vapor chamber device includes a first casing, a first capillary structure, and a second casing. The first casing includes a first plate portion, multiple first protrusions, and a first side wall. The first capillary structure is disposed above an inner 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, multiple second protrusions, and a second side wall. The first side wall is connected to the second side wall, and multiple steam passages are formed between the second protrusions. The second plate portion includes multiple connecting regions yielded by the second protrusions, and the first protrusions are connected to the connecting regions. The second protrusions rest against the first capillary structure. |