To provide a fiber crosslinked body having excellent biodegradability, biocompatibility, water absorptivity and water retentivity, and to provide a method for producing the fiber crosslinked body.

The fiber crosslinked body is produced as follows. A fiber and a fiber assembly containing polyglutamic acid having a molecular weight of 200,000 or more are formed by an electrostatic spinning method. Water and a water-soluble organic solvent are used as a solvent. The fiber diameter of the fiber of the polyglutamic acid formed by the static spinning method is preferably 0.01 to 3 m, more preferably 0.05 to 1.8 m. The fiber and the fiber assembly obtained by the electrostatic spinning method are crosslinked.