To provide a three-dimensional fiber structure with which a fiber reinforced resin can be manufactured in a state of suppressing the appearance of wrinkle and deformation at a folded portion by folding treatment, even when the three-dimensional fiber structure with plate form is used for a reinforced substrate of a fiber reinforced resin with three-dimensional shape having a folded portion.

A three-dimensional fiber structure 11 has a laminated fiber layer 12 in which fiber layers 12a and 12b comprising continuous fibers are laminated with at least two-axis orientation, and the laminated fiber layer 12 is bound with a binding yarn 13 having a portion which is arranged into a crossing direction with the fiber layers 12a and 12b. A spiral yarn is used as the binding yarn 13.