To improve manufacturability of a canister pipe, and to prevent abnormal noise to be caused by a pressure change in gas by prevent a sudden pressure change in the gas flowing in a gas passage.

In this piping structure of the canister provided with a joint having an orifice part in the middle of a purge pipe for connecting a canister and an engine, the joint includes a first hose connecting part for connecting the purge pipe on the canister side and a second hose connecting part for forming an outer diameter smaller than the first hose connecting part and connecting the purge pipe on the engine side. A bell-mouth part is formed at the end of the first hose connecting part side among a gas passage formed in the joint, while the orifice part is formed on the second hose connecting part side among the gas passage formed in the joint.