In a method for lining tunnel walls or ceilings with protective nets or the like, web-shaped protective net material is unwound from a reel and is fastened to the tunnel walls or ceiling by tie bolts. The reel is rotatably arranged. The rotation of the reel about a shaft is controlled in order to unwind the protective net material, the shaft being mechanically moved in steps along the tunnel walls or ceiling together with the reel. The protective net material unwound in each step is preferably stretched and mechanically fastened. The individuals carrying out these processes are thus not exposed to any direct risk, while the lining process can be accelerated.