To improve the effect of pressure for the massage unit of mounting a treating roller on the arm, which moves reciprocating motion based on the rotational strength of eccentric wheel, by rotating the treating roller eccentrically with synchronizing to the eccentric direction of eccentric wheel.

An eccentric wheel 13, which its axis is eccentric predetermined width from the center, is fixed on the both sides of axis of rotation 12 to rotate with axis of rotation 12 integrally. An eccentric wheel 13 is inserted into a slide piece 14 with play. The slide piece 14 is fixed to slidably to vertical direction of the long hole of arm 16 that is connected and inclined to a pivot 15 and the arm 16 is moved reciprocation movement vertical direction against the pivot 15 as a base point with the rotational strength of eccentric wheel 13. When the eccentric wheel 13 rotates with the axis of rotation 12 integrally, a treating roller 4 synchronizes the reciprocation movement of the arm 16 with the stroke that is corresponding to the eccentric width of eccentric wheel 13, then the reciprocation movement with the stroke that is corresponding to the eccentric width S of treating roller 4 against the treating shaft is add.