An evaporated fuel treatment device, comprising: a fuel tank configured to store fuel for an internal combustion engine; a canister configured to collect evaporated fuel generated in the fuel tank; an evaporated fuel passage configured to connect the fuel tank to the canister; a valve member disposed in the evaporated fuel passage and configured to open/close the evaporated fuel passage; an inlet pipe disposed in the fuel tank and configured to feed the fuel; a breather pipe configured to communicate the fuel tank with the inlet pipe; a tank internal pressure sensor configured to detect an internal pressure of the fuel tank; a control unit configured to control opening/closing of the valve member; and an operation unit to be operated when a fueling operation is performed, wherein, when the operation unit is operated and fueling control is started, the control unit is configured to open the valve member so as to release the internal pressure of the fuel tank, and the control unit is configured to close the valve member after release of the internal pressure in the fuel tank, and wherein an upper space disposed above a fuel level in the fuel tank is sealed when the fuel level in the fuel tank reaches the breather pipe during feeding the fuel to the fuel tank through the inlet pipe while the valve member is being closed, characterized in that, after the valve member is closed during the fueling control, the control unit is configured to open the valve member so as to release the internal pressure in the fuel tank and then the control unit is configured to close the valve member after release of the internal pressure in the fuel tank, under a condition that the internal pressure in the fuel tank is equal to or more than a first predetermined value and furthermore a rising speed of the internal pressure in the fuel tank is less than a second predetermined value, and wherein, after the valve member is closed during the fueling control, the control unit is configured to maintain a closed state of the valve member, under a condition that the internal pressure in the fuel tank is equal to or more than the first predetermined value and furthermore the rising speed of the internal pressure in the fuel tank is equal to or more than the second predetermined value. a fuel tank configured to store fuel for an internal combustion engine; a canister configured to collect evaporated fuel generated in the fuel tank; an evaporated fuel passage configured to connect the fuel tank to the canister; a valve member disposed in the evaporated fuel passage and configured to open/close the evaporated fuel passage; an inlet pipe disposed in the fuel tank and configured to feed the fuel; a breather pipe configured to communicate the fuel tank with the inlet pipe; a tank internal pressure sensor configured to detect an internal pressure of the fuel tank; a control unit configured to control opening/closing of the valve member; and an operation unit to be operated when a fueling operation is performed, wherein, when the operation unit is operated and fueling control is started, the control unit is configured to open the valve member so as to release the internal pressure of the fuel tank, and the control unit is configured to close the valve member after release of the internal pressure in the fuel tank, and wherein an upper space disposed above a fuel level in the fuel tank is sealed when the fuel level in the fuel tank reaches the breather pipe during feeding the fuel to the fuel tank through the inlet pipe while the valve member is being closed, characterized in that, after the valve member is closed during the fueling control, the control unit is configured to open the valve member so as to release the internal pressure in the fuel tank and then the control unit is configured to close the valve member after release of the internal pressure in the fuel tank, under a condition that the internal pressure in the fuel tank is equal to or more than a first predetermined value and furthermore a rising speed of the internal pressure in the fuel tank is less than a second predetermined value, and wherein, after the valve member is closed during the fueling control, the control unit is configured to maintain a closed state of the valve member, under a condition that the internal pressure in the fuel tank is equal to or more than the first predetermined value and furthermore the rising speed of the internal pressure in the fuel tank is equal to or more than the second predetermined value.