To provide a reliable plastic cladding-coated optical fiber in which the average breakage strength is large and variation in the break strength is small, and the breakage strength in the longitudinal direction is stable, and to provide a method of manufacturing the plastic coated optical fiber.

The plastic coated optical fiber 6 is formed of a primary plastic clad coated optical fiber 4 composed of a clad layer 2 made of a fluoresin such as ultraviolet-curing fluoride acrylate resin and a ultraviolet-curing layer 3 made of a ultraviolet curable resin, provided on the outer periphery of core glass 1, made of silica based glass, such as, pure silica successively in the direction separating from the core glass 1; and a resin coat layer 5 composed of a fluorine system thermoplastic resin such as ethylene-tetrafluoroethylene copolymer (ETFE) which is extrusion-coated on the outer periphery of the primary plastic clad optical fiber.