To ensure the reading surface in the vicinity of the seeing line of a reading posture of a user such as facing upward, downward or sideways along the shape of a sliding arm by attaching a book holding base to which a book is attached to the sliding arm when the book is read without holding it such as in bed.

A column 24 is attached under a fixed state to a bed 36 by utilizing a side rail attaching hole 38 of the bed 36, and an arm receiver 25 is vertically movably and holdably attached to the column 24. To the arm receiver 25, the vertical shaft 13a of this sliding arm 10a is vertically movably, rotatably and holdably attached. A curved sliding shaft 14 is constituted of a rising section 17 which is extended while being connected with a neck section 12a at the lower section of the vertical shaft 13a, a curved section 16 and a horizontal section 15. The book holding base 34 to which the book is attached is attached to the distal end of the horizontal section 15 in a fixed state. Then, the book holding base 34 is rotatably holdably moved within a sliding range 33a.