An optical fiber ribbon holding member capable of readjusting a position of an optical fiber ribbon without requiring a heating operation is provided. A holding member main body that has a U-shaped cross section and a space to which a plurality of optical fiber ribbons can be accommodate in a laminated state, and a lid body an opening surface of which has a reverse U-shaped cross section are employed. A latch structure is formed on wall portions of a lid body and a holding member main body, and engages to each other when the lid body covers the holding member main body. Heating operation is not required, and the optical fiber ribbons are held by only a simple operation of covering the lid body, so that the operation of holding the optical fiber ribbons is easily performed and readjustment of the position of the optical fiber ribbons can be performed.