To provide a piping joint which can easily detect breakage or the like of a metal washer by airtight inspection.

The piping joint comprises a male block 110, a female block 130, the annular metal washer 160, an O-ring 180, a through-hole 141, and a stopper 190. The male block 110 is provided with a cylindrical convexity 120 formed at the outer peripheral part of a first opening 113, and the female block 130 is provided with a concavity 140 at the outer peripheral part of a second opening 133. The concavity 140 is provided in a concave state so that it can house the cylindrical convexity 120. The annular metal washer 160 placed between the tip surface of the cylindrical convexity 120 and the undersurface of the concavity 140 makes the first opening 113 communicate with the second opening 133 and secures sealing performance. The O-ring 180 is brought into intimate watertight contact with both the outer peripheral surface of the cylindrical convexity 120 and the inner peripheral surface of the concavity 140, and a cylindrical waterproofing space 181 is formed between the O-ring 180 and the metal washer 160. The concavity 140 facing the waterproofing space 181 is opened, and the through-hole 141 penetrates from the waterproofing space 181 to the outside. The stopper 190 formed of an elastic member is engaged with the through-hole 141 and covers the through-hole 141 in a watertight state.