To provide a product of high reliability which ensures a contact even when distortion is caused in a fixed insulating board holding a fixed contact, in a no-voltage tap changer which changes a tap of a primary winding in a no-voltage state.

The no-voltage tap changer includes: a fixed contact unit 10 wherein fixed contacts 11 of line contact and point contact are arranged in parallel on the fixed insulating board 12; a movable contact unit 20 wherein movable contacts 21 of plane contact are supported while facing on the inner sides of movable insulating boards 22 arranged in parallel back and forth, and a pair of front and rear movable contacts 21 sandwich the adjacent fixed contacts 11 by a U-shaped blade spring 24 provided to the outside of the movable insulating boards; and a driving unit 30 which moves the movable contact unit at the time of steady conducting to the time of tap changing. The movable insulating board is so set as to have a thickness which has: flexibility allowing deformation coping with distortion of the parallel condition of the fixed contacts by holding force of the blade spring during steady conducting, even when the parallel condition of the fixed contacts is distorted due to distortion of the fixed insulating board; and rigidity allowing movement in a form along the parallel condition of the fixed contacts at the time of tap changing; at the same time.