A resin substrate includes an insulating base material in which conductive particles are mixed with resin, and conductor patterns provided on the principal surfaces of the insulating base material. When a length at a position at which a distance between two conductor patterns that are adjacent to each other without directly electrically connecting to each other on the same principal surface of the insulating base material is smallest is indicated by L1 and a length at a position at which a distance between two conductor patterns that face each other without directly electrically connecting to each other between the different principal surfaces of insulating base materials is smallest is indicated by L2, L1 is larger than or equal to L2 (L1 ≥L2).