A fuel injection valve damping insulator damps vibration produced in a fuel injection valve (11). A damping insulator (30) is interposed between a shoulder portion (18) of a cylinder head and a tapered surface (24) of the fuel injection valve (11) that faces the shoulder portion. The damping insulator (30) includes an annular tolerance ring (33) that abuts against the tapered surface (24), and an elastic member (36) that is arranged between the tolerance ring (33) and the shoulder portion (18). An annular coil spring (34) and a sleeve (35) are each embedded juxtaposed in the elastic member (36). A height (H2) of the sleeve (35) is formed lower than an outer diameter (H1) of individual small ring portions that form a helix of the coil spring (34), and at least one of a tolerance ring (33) side and a shoulder portion (18) side of the sleeve (35) is buried in the elastic member (36).