To provide a molecular beam source cell for Al that can maintain a uniform spatial intensity distribution without breaking the molecular beam source cell.

The molecular beam source cell 1 includes a crucible 10 which houses a raw material to be vaporized, and a molecular beam source heater portion 12 which surrounds a side face of the crucible 10 to heat the crucible 10. The crucible 10 includes a bottomed cylindrical container provided with an annular opening 16 at an upper end, and a flange 11 which is arranged outwardly over the entire periphery of the opening 16 of the container, and protrudes to outside the molecular beam source heater portion 12.