To eliminate the problem that a conventional switch functioning as a cover interlocked switch and as a safety switch sensing abnormal vibration of a washing tub has a complicated structure and operates unstably.

The safety switch is constituted to operate on sensing abnormal vibration in centrifugal dewatering operation of a washing machine. The safety switch has a safety switch body fitted to the frame body of a washing machine body and a downward projecting lever making the safety switch operate on sensing abnormal vibration of an extracted water receiving tub supported in suspension by a vibrationproof mechanism in the the washing machine body. This lever is supported rotatably at a support point of the safety switch body, while an opening-closing lever part of a switch contact is provided in annexation above the support point of rotation of the lever. Two contact plates opposite each other are provided parallel in the direction of movement thereof, on the opposite sides of the opening-closing lever part. The two contact plates are opened and closed by sliding of the opening-closing lever. Moreover, they are opened and closed by sliding of the cover interlocked lever positioned on the outer sides of the two opposite contact plates, associated with the cover of a washing throw-in opening of the washing machine.