In a back massaging apparatus capable of projecting a massaging mechanism forward and returning the same to an original normal position, upon securing a motion amount to be sufficient, the back massaging apparatus is intended to be thinned in the back and forth direction and allow a backrest part as a chair-type massaging machine to be suppressed from thickening. A back massaging apparatus (4) of the present invent ion provided in a chair-type massaging machine (1) includes: a massaging mechanism (10) having: left and right paired massaging members (17) each of which is provided with a treatment unit (21) performing a massaging operation and a drive unit (18) transmitting a massaging operation to the massaging members (17) a base member (12) which supports the massaging mechanism (10) in a state of the massaging members (17) facing forward a vertical movement mechanism (13) allowing the base member (12) to move vertically within a backrest part (3) and a projection amount variable mechanism (14) which moves the massaging members (17) so that a projection amount of the treatment unit (21) in the back and forth direction is varied.在能使按摩機構朝前方突出或回到原來的通常位置之背部揉捏裝置,使其除了確保具有充分量的動作量之外,還能謀求背部揉捏裝置的前後方向之薄型化,抑制作為椅子型按摩機而言靠背部變的很厚。椅子型按摩機(1)所具備的本發明之背部揉捏裝置(4)具有:按摩機構(10),係具有:具備進行按摩動作的施療器(21)且配備成左右一對之按摩構件(17)、及將按摩動作傳動至該按摩構件(17)之驅動部(18);基座構件(12),係於按摩構件(17)朝向前方之狀態下支撐按摩機構(10);上下移動機構(13),可使基座構件(12)在靠背部(3)內朝上下方向移動;以及突出量可變機構(14),係使按摩構件(17)移動,以使施療器(21)的前後方向之突出量改變。10‧‧‧按摩機構12‧‧‧基座構件14‧‧‧突出量可變機構17‧‧‧按摩構件18‧‧‧驅動部20‧‧‧支撐臂21‧‧‧施療器23‧‧‧揉捏驅動部24‧‧‧搥打驅動部25‧‧‧傾斜旋轉構件26‧‧‧第1旋轉軸27‧‧‧揉捏馬達28‧‧‧防振機構31‧‧‧第2旋轉軸32‧‧‧搥打馬達34‧‧‧偏心驅動體35‧‧‧殼體36‧‧‧曲柄軸38‧‧‧第1軸承部39‧‧‧齒輪頭45‧‧‧引導輥
