To make it possible to not only realize easily openable pages but also enhance designability and to form highly recognizable patterns or characters on a cut-out surface on a fore edge side.

In order to produce this book with its fore edge obliquely cut, a book 10, which is collected under a state being bound together, is prepared so as to form an obliquely cut surface A on a fore edge by executing the trimming the fore edge under the state that the collected book 10 is so deformed as to be bent from its back to its fore edge in order to rectilinearly lean the cut surface A on the fore edge side to its back side and, at the same time, to form a pattern on the fore edge by the edge parts of respective pages exposed on the fore edge side under the constitution that a plurality of pages, on which one and the same pattern is respectively arranged, are bound together at the same position of the fore edge side.