We have been developing a diamond wheel that uses a thermoplastic resin as a bonding material to obtain the same surface properties as polishing by grinding alone. In this study, roughness was measured after grinding the ends of optical fiber used in telecommunications with wheels of different grain sizes, using dry or wet grinding. A mirror-finished surface on the end face of the optical fiber was achieved with dry grinding using a thermoplastic resin bonded wheel with grain size finer than #6000. The optical connection loss between optical fibers was less than the general specification value of 0.1 dB.