An inside leaflet of a book is provided which is bond-bound with pages of the book to provide an advertisement. The inside leaflet includes an advertisement printed part and a binding part. Catchphrases or illustrations for advertisement are printed on at least one side of the advertisement printed part. The binding part is configured to be bound with the pages along an edge of the inside leaflet such that the binding part has less binding portions than those of the pages in order to leave no traces or marks when the inside leaflet is detached from the book. Accordingly, since the inside leaflet is able to be bound to pages of various kinds of books and easily removed from the books without leaving any traces or marks in the books, the inside leaflet contributes to extension of the application range of advertisements and improvement of advertisement efficiency.