A transmission line, which has a mesh-structure signal metal, is presented in this work for standard CMOS processes. It is desirable for a transmission line in a CMOS IC to be small in size and have low insertion loss. We propose a novel transmission line with large phase constant so that the circuit element using the proposed line can be constructed with a small area. This paper explains the proposed transmission line structure using mesh-structure signal metal and presents experimental results. This paper also describes a suitable type of transmission line for millimeter-wave CMOS IC. With the proposed transmission line, the element size can be reduced by 8.2% compared with that of the conventional one.