Method of producing long body

A method of producing a long body covered with a covering layer, wherein

• the long body at least includes a plural covering targets selected from a group consisting of electric wires and tubes,
• the covering layer at least includes an intermediate layer and an outermost layer,
• the intermediate layer employs a resin film having a density ρ1 of 0.2 g/cm3 or more and 1.8 g/cm3 or less and having a PV1 value, which is a surface peak-to-valley value, of 5 μm or more,
• the outermost layer employs a resin film having a density ρ2 of 1.2 g/cm3 or more and 2.5 g/cm3 or less,
• the method comprises at least:
• covering the long body with the covering layer;
• and
• fixing positions of the plural covering targets, and
• the following formulas (1) and (3) are satisfied in the case that a PV2 value, which is a surface peak-to-valley value, of the outermost layer is 5 μm or less, and the following formulas (2) and (3) are satisfied in the case that the PV2 value is larger than 5 μm:
• PV1−PV2≥2 μm (1)
• PV2−PV1>0 μm (2)
• ρ2−ρ1≥0.1 g/cm3 (3)