A processing machine suitable for performing additive manufacturing processing for a workpiece with a molten material, the processing machine comprising: a first cover having a first wall and a second wall that face each other in a horizontal direction and defining a processing area between the first wall and the second wall, the first wall being provided with a first opening allowing a gas to flow into the processing area, the processing machine further comprising a flow generator configured to generate a gas flow flowing from below to upward along the second wall, the first cover being provided with a second opening allowing the gas to flow out from the processing area, the processing machine further comprising a second cover defining an accommodation space and accommodating, in the accommodation space, a material powder supply device configured to supply a powder material toward the processing area, the flow generator including: a first blower configured to supply a gas from the accommodation space into the processing area; and a duct configured to feed the gas supplied from the accommodation space into the processing area as a gas flow flowing from below to upward, the processing area and the accommodation space being separated by the second wall, the second wall being provided with a third opening, the duct including an inlet and an outlet, the inlet being open at one end of the duct, the outlet being open at the other end of the duct, and the inlet being overlapped with the third opening, an opening surface of the outlet facing an opening surface of the second opening in a vertical direction. a first cover having a first wall and a second wall that face each other in a horizontal direction and defining a processing area between the first wall and the second wall, the first wall being provided with a first opening allowing a gas to flow into the processing area, the processing machine further comprising a flow generator configured to generate a gas flow flowing from below to upward along the second wall, the first cover being provided with a second opening allowing the gas to flow out from the processing area, the processing machine further comprising a second cover defining an accommodation space and accommodating, in the accommodation space, a material powder supply device configured to supply a powder material toward the processing area, the flow generator including: a first blower configured to supply a gas from the accommodation space into the processing area; and a duct configured to feed the gas supplied from the accommodation space into the processing area as a gas flow flowing from below to upward, the processing area and the accommodation space being separated by the second wall, the second wall being provided with a third opening, the duct including an inlet and an outlet, the inlet being open at one end of the duct, the outlet being open at the other end of the duct, and the inlet being overlapped with the third opening, an opening surface of the outlet facing an opening surface of the second opening in a vertical direction. a first blower configured to supply a gas from the accommodation space into the processing area; and a duct configured to feed the gas supplied from the accommodation space into the processing area as a gas flow flowing from below to upward, the processing area and the accommodation space being separated by the second wall, the second wall being provided with a third opening, the duct including an inlet and an outlet, the inlet being open at one end of the duct, the outlet being open at the other end of the duct, and the inlet being overlapped with the third opening, an opening surface of the outlet facing an opening surface of the second opening in a vertical direction.