A washing machine comprising: a body ; a water tub in the body for storing washing water; a cylindrical washing tub configured to be rotatably provided in the water tub , to accommodate laundry; a plurality of recessed portions formed in an inner circumferential surface of the washing tub and arranged in a circumferential direction of the washing tub to form a pattern ; and first dehydrating holes formed in the respective recessed portions , wherein the respective recessed portions are formed in a length direction of the washing tub , and characterised in that : each recessed portion includes a first inclined portion inclined downwardly in the circumferential direction of the washing tub , a second inclined portion inclined upwardly in the circumferential direction of the washing tub , a flat first connecting portion connecting the first inclined portion and the second inclined portion to each other, and second connecting portions each connecting between the flat first connecting portion and the respective first inclined portion and second inclined portion , and the first dehydrating holes are formed in the flat first connecting portion and arranged such that one of the first dehydrating holes is provided at each end portion of the flat first connecting portion . a body ; a water tub in the body for storing washing water; a cylindrical washing tub configured to be rotatably provided in the water tub , to accommodate laundry; a plurality of recessed portions formed in an inner circumferential surface of the washing tub and arranged in a circumferential direction of the washing tub to form a pattern ; and first dehydrating holes formed in the respective recessed portions , wherein the respective recessed portions are formed in a length direction of the washing tub , and characterised in that : each recessed portion includes a first inclined portion inclined downwardly in the circumferential direction of the washing tub , a second inclined portion inclined upwardly in the circumferential direction of the washing tub , a flat first connecting portion connecting the first inclined portion and the second inclined portion to each other, and second connecting portions each connecting between the flat first connecting portion and the respective first inclined portion and second inclined portion , and the first dehydrating holes are formed in the flat first connecting portion and arranged such that one of the first dehydrating holes is provided at each end portion of the flat first connecting portion . each recessed portion includes a first inclined portion inclined downwardly in the circumferential direction of the washing tub , a second inclined portion inclined upwardly in the circumferential direction of the washing tub , a flat first connecting portion connecting the first inclined portion and the second inclined portion to each other, and second connecting portions each connecting between the flat first connecting portion and the respective first inclined portion and second inclined portion , and the first dehydrating holes are formed in the flat first connecting portion and arranged such that one of the first dehydrating holes is provided at each end portion of the flat first connecting portion . <EOS>