An evaporated fuel processing apparatus preventing evaporated fuel from being discharged out of a canister when residual purge gas is made to return to the canister and processed is provided. In the apparatus, an ECU performs residual purge gas processing operation of returning the residual purge gas into the canister and processing during halt of purge control. This operation includes a residual purge gas pressure-feeding process of pressure-feeding the residual purge gas with the air into the canister by the purge pump in a state in which the atmospheric passage is shut off and the purge passage and the second bypass passages are opened and an air discharge process of discharging the air in the canister outside via the atmospheric passage by opening the atmospheric passage while the purge passage and the second bypass passage are shut off.