The present invention addresses the problem of providing a monoclonal antibody or fragment thereof that binds to human CC chemokine receptor 1 (CCR1) and blocks the activation of human CCR1. The present invention relates to: a monoclonal antibody or a fragment thereof that binds to the extracellular region of human CCR1 and blocks the activation of human CCR1 by human CC chemokine ligand 15 (CCL15)； a hybridoma that produces said antibody； a nucleic acid having a base sequence encoding said antibody or fragment thereof； a transformed cell including a vector that includes said nucleic acid； a method for producing said antibody or fragment thereof using said hybridoma or said transformed cell； a therapeutic agent and a diagnostic agent including said antibody or fragment thereof； and a treatment method and a diagnosis method for CCR1-related diseases using said antibody or fragment thereof.
