To protect a waveguide or cable in an installation channel, a protective profile is inserted into the channel and has a substantially U-shaped cross-section when installed. To install this in the channel, an apparatus having a drum with a profile wound thereon has the profile unwound and guided by guide rolls to a press roll, which presses the profile into the channel to the desired depth. The profile can have a center portion provided with embedded reinforcing elements or even optical or electrical leads.