To provide an evaporated fuel treating device versatile to various types of vehicles and including an aspirator for adjusting a fuel injection amount from a nozzle part.

The evaporated fuel treating device includes a canister 10 adsorbing evaporated fuel, a first vapor passage 2 leading the evaporated fuel from a fuel tank 1 to the canister 10, a first recovery passage 3 recovering the evaporated fuel into the fuel tank 1, and the aspirator 12 generating negative pressure by using a part of fuel F discharged from a fuel pump 11, sucks in and recoveries the evaporated fuel with the negative pressure by the aspirator 12. The aspirator 12 includes an introduction port 46 for fuel, a suction port 43 for the evaporated fuel, the nozzle part 48 for injecting the fuel, etc. In the aspirator 12, there is provided a needle valve 50 which is arranged for advancing and retreating in the axial direction and can adjust the fuel injection amount from the nozzle part 48 according to its advance or retreat position.