A wound dressing material comprising a particle comprising a crosslinked gelatin derivative, the gelatin derivative comprising the structure represented by the following formula (1): GltnNH-CHR1R2 (1)wherein "Gltn" represents a gelatin residue, R1 represents an alkyl group having 1-17 carbon atoms, and R2 represents a hydrogen atom or an alkyl group having 1-17 carbon atoms, andthe particle having a particle size ranging from 1 to 1,000 µm.