A massage unit includes a treatment member; an arm that supports the treatment member; a drive shaft that supports the arm and causes the treatment member to approach and be separated with respect to a treatment target site; a movable portion that causes the treatment member to be operable in a direction of being separated from the treatment target site when the treatment member comes into contact with the treatment target site by a force equal to or greater than predetermined strength; and biasing means for biasing the treatment member in an approaching direction.