A vacuum is maintained inside a vacuum partition (1). The whole of the solid packed container (3) is disposed inside the vacuum partition (1). A heater (7) sublimates the aluminum chloride (8) packed in the solid packed container (3) to generate an aluminum chloride gas (9). An arc chamber (6) ionizes the aluminum chloride gas (9) and emits an ion beam (11) of the ionized aluminum chloride gas (9). A gas supply nozzle (10) leads the aluminum chloride gas (9) from the solid packed container (3) into the arc chamber (6). A supporting part (4) supports and fixes the solid packed container (3) on the vacuum partition (1). A thermal conductivity of the supporting part (4) is lower than thermal conductivities of the vacuum partition (1) and the solid packed container (3).