To provide a notebook cover with a pen holder configured so that the pen holding part has excellent strength, other belongings stored in the bag are prevented from being scratched by the tip of writing instrument inserted into the pen holding part, also, the writing instrument is easily inserted into the pen holding part, and the narrow-diameter writing instrument with no clip hardly drops off the pen holding part, and the pen holding part does not interrupt the high-class feeling of the notebook cover.

Regarding the notebook cover with a pen holder 1, the pen holding part 8 of one of an outer cover 3 is formed by folding one end portion 5f of a cover body member 5a constituting the cover body 5 toward a folding portion 2, and making one end portion 5f of the cover body member 5a vertically face the cover body member 5a and bonding them so as to have a cylindrical shape, and a pen insertion port 8b that is inclined from upward to downward is provided at the upper part of the pen holding part 8, from the bonded portion 8a where one end portion 5f of the cover body member 5a is bonded, to the outside as the opposite side of the folding portion 2.