Abstract: A coaxial cable which is highly flexible and in which bending causes very little change in electrical characteristics is disclosed. Inner and outer conductors, each provided as a corrugated tube, are arranged coaxially with a thermoplastic resin insulating member therebetween. The insulating member is composed of a spiral rib joined to an outer insulating tube. The spiral rib is made of high density polyethylene and the insulating tube of low density polyethylene. The ratio of the corrugation pitch of the inner conductor to the pitch of the outer conductor is in a range of 0.9 to 1.2.