A washing machine comprising: a washing tub configured to accommodate a washing object and wash water; a pressurizing and depressurizing part having a pressing part configured to freely advance to and retreat from the washing object accommodated in the washing tub; and a controller configured to control the pressurizing and depressurizing part, wherein the pressurizing and depressurizing part is configured to press and release pressing against the washing object by using the pressing part to cause the washing object to contract and expand, so that water currents in multiple directions are generated inside the washing object, and the washing machine comprises a plurality of the pressing parts, and the pressurizing and depressurizing part is configured to press and release pressing against the washing object by using the pressing parts to cause the washing object to contract and expand, so that the water currents in multiple directions are generated inside the washing object, and the washing machine comprises a plurality of the pressurizing and depressurizing parts, each of the pressurizing and depressurizing parts includes: one of the pressing parts configured to expand and contract; a pressurizing pump configured to supply the fluid into corresponding one of the pressing parts; and a discharge valve configured to discharge the fluid inside corresponding one of the pressing parts, and the controller is configured to control the pressurizing and depressurizing parts so that each of the pressing parts expands and contracts at an arbitrary timing. a washing tub configured to accommodate a washing object and wash water; a pressurizing and depressurizing part having a pressing part configured to freely advance to and retreat from the washing object accommodated in the washing tub; and a controller configured to control the pressurizing and depressurizing part, wherein the pressurizing and depressurizing part is configured to press and release pressing against the washing object by using the pressing part to cause the washing object to contract and expand, so that water currents in multiple directions are generated inside the washing object, and the washing machine comprises a plurality of the pressing parts, and the pressurizing and depressurizing part is configured to press and release pressing against the washing object by using the pressing parts to cause the washing object to contract and expand, so that the water currents in multiple directions are generated inside the washing object, and the washing machine comprises a plurality of the pressurizing and depressurizing parts, each of the pressurizing and depressurizing parts includes: one of the pressing parts configured to expand and contract; a pressurizing pump configured to supply the fluid into corresponding one of the pressing parts; and a discharge valve configured to discharge the fluid inside corresponding one of the pressing parts, and one of the pressing parts configured to expand and contract; a pressurizing pump configured to supply the fluid into corresponding one of the pressing parts; and a discharge valve configured to discharge the fluid inside corresponding one of the pressing parts, and the controller is configured to control the pressurizing and depressurizing parts so that each of the pressing parts expands and contracts at an arbitrary timing.