A hydrogen generation device adapted to a fuel cell is provided. The hydrogen generation device includes a containing tank and a buffer layer. The buffer layer is disposed in the containing tank and divides the containing tank into a first containing space and a second containing space. The first containing space is capable of containing a liquid reactant. The second containing space is capable of containing a first solid fuel. The liquid reactant is capable of entering the second containing space through the buffer layer and reacts with the first solid fuel to generate hydrogen.