Multi-core cable and signal transmission path

A multi-core cable, comprising:

• a plurality of coaxial cables being arranged in parallel with each other;
• and
• a covering member comprising a synthetic resin and collectively covering the plurality of coaxial cables,
• wherein each of the plurality of coaxial cables comprises a center conductor, an insulator covering an outer periphery of the center conductor, and an outer conductor comprising a metal and covering an outer periphery of the insulator,
• wherein the covering member is configured to hold the plurality of coaxial cables in such a manner that the plurality of coaxial cables are aligned side by side along a direction perpendicular to a longitudinal direction of the plurality of coaxial cables,
• wherein at least a part of respective outer conductors of the plurality of coaxial cables contacts the covering member,
• wherein a gap is formed between the covering member and at least a part of an outer periphery of the outer conductor in a cross-section perpendicular to the longitudinal direction of the plurality of coaxial cables, and
• wherein the gap comprises a space in which the covering member enters between the plurality of coaxial cables.