A dishwasher comprising: a tub forming a washing chamber; and a blowing unit configured to blow air into the tub, wherein the blowing unit comprises: a housing having an inner space and a discharge port through which air is discharged into the tub; a blowing fan disposed inside the housing; and a valve comprising a rotation shaft, an opening/closing part, and a weight part, and wherein the housing comprises a flow passage formed between the blowing fan and the discharge port to guide air blown from the blowing fan into the tub and in which the valve is disposed, and a rotation region in which the weight part is rotatably provided, wherein the valve is configured to be rotated about the rotation shaft between a closed position, A, in which the opening/closing part blocks the flow passage and an open position, B, in which the opening/closing part opens the flow passage, and wherein the valve is configured to be rotated from the closed position to the open position by air flow generated by the blowing fan when the blowing fan is operated, and is configured to be rotated from the open position to the closed position by the weight of the weight part after the blowing fan is operated, wherein the blowing unit further comprises a stopper to restrict the rotation of the valve, characterised in that, the weight part is positioned on the opposite side of the rotation shaft from the opening/closing part, and the stopper is configured such that a first end of the stopper is in contact with the opening/closing part when the valve is disposed in the open position, and a second end of the stopper is in contact with the weight part when the valve is disposed in the closed position. a tub forming a washing chamber; and a blowing unit configured to blow air into the tub, wherein the blowing unit comprises: a housing having an inner space and a discharge port through which air is discharged into the tub; a blowing fan disposed inside the housing; and a valve comprising a rotation shaft, an opening/closing part, and a weight part, and wherein the housing comprises a flow passage formed between the blowing fan and the discharge port to guide air blown from the blowing fan into the tub and in which the valve is disposed, and a rotation region in which the weight part is rotatably provided, wherein the valve is configured to be rotated about the rotation shaft between a closed position, A, in which the opening/closing part blocks the flow passage and an open position, B, in which the opening/closing part opens the flow passage, and wherein the valve is configured to be rotated from the closed position to the open position by air flow generated by the blowing fan when the blowing fan is operated, and is configured to be rotated from the open position to the closed position by the weight of the weight part after the blowing fan is operated, wherein the blowing unit further comprises a stopper to restrict the rotation of the valve, characterised in that, a housing having an inner space and a discharge port through which air is discharged into the tub; a blowing fan disposed inside the housing; and a valve comprising a rotation shaft, an opening/closing part, and a weight part, and wherein the housing comprises a flow passage formed between the blowing fan and the discharge port to guide air blown from the blowing fan into the tub and in which the valve is disposed, and a rotation region in which the weight part is rotatably provided, wherein the valve is configured to be rotated about the rotation shaft between a closed position, A, in which the opening/closing part blocks the flow passage and an open position, B, in which the opening/closing part opens the flow passage, and wherein the valve is configured to be rotated from the closed position to the open position by air flow generated by the blowing fan when the blowing fan is operated, and is configured to be rotated from the open position to the closed position by the weight of the weight part after the blowing fan is operated, wherein the blowing unit further comprises a stopper to restrict the rotation of the valve, characterised in that,