A wound dressing material includes a particle having a crosslinked gelatin derivative, the gelatin derivative having 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, and the particle having a particle size ranging from 1 to 1,000 μm.