Method for variable extraction of argon by cryogenic separation, in which - feed air (1, 4, 7) is cooled in a main heat exchanger, - cooled feed air (9, 13) is introduced into a distillation column system, which has a high-pressure column and a low-pressure column, - an argon-enriched flow is introduced from the low-pressure column into a crude argon column (81, 82), - a crude argon fraction is drawn off in gaseous form from the head of the crude argon column (81, 82) or from the head condenser thereof, - the crude argon fraction is introduced in gaseous form into a pure argon column, - a liquid pure argon product flow is removed from the sump of the pure argon column and - in a first operating mode, a first pure argon product quantity is discharged as an end product, characterized in that - in a second operating mode, a second pure argon product quantity is discharged as an end product quantity, which is smaller than the first pure argon product quantity, and - in the second operating mode, - a gaseous argon return flow (101, 103) is drawn off at one or more of the following locations: - crude argon column (81, 82), - head condenser of the crude argon column, - pure argon column, - head condenser of the pure argon column, - in the first operating mode, no gaseous argon return flow is drawn off, or a quantity of argon return flow that is lower than in the second operating mode is drawn off, - wherein the argon content of the gaseous argon return flow (101, 103) is at least twice as high as that of the argon-enriched flow from the low-pressure column, - the gaseous argon return flow (101, 103) is heated in the main heat exchanger, and - at least a portion of the gaseous argon return flow (101, 103) is heated without mixing with another flow in a separate passage of the main heat exchanger. - feed air (1, 4, 7) is cooled in a main heat exchanger, - cooled feed air (9, 13) is introduced into a distillation column system, which has a high-pressure column and a low-pressure column, - an argon-enriched flow is introduced from the low-pressure column into a crude argon column (81, 82), - a crude argon fraction is drawn off in gaseous form from the head of the crude argon column (81, 82) or from the head condenser thereof, - the crude argon fraction is introduced in gaseous form into a pure argon column, - a liquid pure argon product flow is removed from the sump of the pure argon column and - in a first operating mode, a first pure argon product quantity is discharged as an end product, characterized in that - in a second operating mode, a second pure argon product quantity is discharged as an end product quantity, which is smaller than the first pure argon product quantity, and - in the second operating mode, - a gaseous argon return flow (101, 103) is drawn off at one or more of the following locations: - crude argon column (81, 82), - head condenser of the crude argon column, - pure argon column, - head condenser of the pure argon column, - in the first operating mode, no gaseous argon return flow is drawn off, or a quantity of argon return flow that is lower than in the second operating mode is drawn off, - wherein the argon content of the gaseous argon return flow (101, 103) is at least twice as high as that of the argon-enriched flow from the low-pressure column, - the gaseous argon return flow (101, 103) is heated in the main heat exchanger, and - at least a portion of the gaseous argon return flow (101, 103) is heated without mixing with another flow in a separate passage of the main heat exchanger. - a gaseous argon return flow (101, 103) is drawn off at one or more of the following locations: - crude argon column (81, 82), - head condenser of the crude argon column, - pure argon column, - head condenser of the pure argon column, - crude argon column (81, 82), - head condenser of the crude argon column, - pure argon column, - head condenser of the pure argon column, - in the first operating mode, no gaseous argon return flow is drawn off, or a quantity of argon return flow that is lower than in the second operating mode is drawn off, - wherein the argon content of the gaseous argon return flow (101, 103) is at least twice as high as that of the argon-enriched flow from the low-pressure column, - the gaseous argon return flow (101, 103) is heated in the main heat exchanger, and - at least a portion of the gaseous argon return flow (101, 103) is heated without mixing with another flow in a separate passage of the main heat exchanger.