To provide an automatic bookmarker by which a page piece of paper is stably and automatically indicated without being fallen down from a book.

The automatic bookmarker comprises a lower side page pinching sheet 12 provided with a base end pinching part 13 with a pair of bearing parts 14 on two facing sides 13a and 13b and a lower side pinching part 18, an upper side page pinching sheet 22 provided with a base end pressing part 23 for opening operating action and an upper side pinching part 27, a thin piece of a magnet 20 enabling them to magnetically contact with each other, and a connecting piece 32 for connecting the lower side page pinching sheet 12 with a pinching piece 22 of the upper side page pinching sheet side. The upper side page pinching sheet 22 is provided with a standing piece part 28 placed so as to make the height of the face of the base end pressing part 23 higher than the upper side pinching part side. The connecting piece 32 is provided with a pair of supporting shaft parts 34 and 35 respectively supported by obliquely formed shaft supporting holes 15 of the bearing parts 14, a female screw part 36 freely screwed with a male screw material 29 inserted from a through-hole 26 of the base end pressing part 23, and a flexible bookmarker part 38 freely pressing the surface side of a page piece of paper of the book. The lower side page pinching sheet 12 and the upper side page pinching sheet 22 are integrated by the connecting piece 32.