To obtain a slot type optical cable which allows the additional laying of coated optical fibers and facilitates pipe taking-out work.

A plurality of resin pipes 2 are continuously disposed in a longitudinal direction around tensile strength materials 1 arranged at a center. A foamed resin 3 is so disposed as to be packed around the resin pipes 2. The outer side of the foamed resin 3 is provided with a grooved spacer 4 by a solid type resin layer. Coated optical fibers 6 are housed in optical fiber housing grooves 5. Retaining windings 7 are applied thereon and are coated thereon with a sheath 8.