To provide a channel base 1 to easily cope with when an opening 2 for incoming/outgoing wire is required.

Related to the channel base 1, openings 2a and 2b for incoming/outgoing wires are formed on an upper surface 1a and a front surface 1b. The opening 2b provided on the front surface 1b extends as far as the bottom 1c of the front surface 1b of the channel base 1. A frame fixture 3 is fixed near the left and right ends of the opening 2b. A cosmetic plate 5 is used to cover from the upper end of the frame fitting 3 to the upper end 2c of the opening 2b.