PURPOSE: To provide a housing method by which a high pressure gas cylinder that is axially slender and weighty can be carried laterally to a travel direction free position on the loading platform of a truck without requiring human power whatsoever.

CONSTITUTION: The head portion of a gas cylinder propped against the side part of a loading platform 1 is supported by means of a suspension stopper 3g that has been moved to one end of a beam 5 provided laterally on the truck loading platform 1, and one end of the beam 5 is lifted up to a predetermined position, and the suspension stopper 3g is pulled into the interior side of the loading platform 1, and when the gas cylinder head portion reaches the predetermined position of the loading platform 1 by this pulling-in, the interior side of the beam 5 is lowered, and the gas cylinder is laid on the loading platform 1.