To develop function as a paper presser and a bookmaker corresponding to large and small books by vertically attaching and fixing an inverted L-shaped vertical rod part to the right-hand part of a base plate provided with a holding part holding the cover of a book and opening and closing a key-shaped page pressing part by a spring.

A page pressing part 2 having an almost inverted L-shape as a whole and formed into an almost key shape at one end of the lower part thereof and having an elastomer 1 provided to the leading end thereof as a page slip preventing element is provided and a raising part 3 and a spring hooking part 4 are provided to the lower part thereof. An inverted L-shaped vertical rod part is loosely passed through a lead tubular element 6 to be mounted in a freely resolvable manner and the leaf tubular element is vertically fixed to the right-hand part of a plate 8 having an insertion type holding part 7 composed of an elastic material and having another spring hooking part 5 provided to the right-hand part of the lower part thereof. Both ends of a pull spring 9 are hooked with the spring hooking parts 4, 5 to open and close the page pressing part 2 by the force of the spring 9. By this constitution, function as a page presser and a bookmarker can be developed corresponding to large and small books.