A control method executed by a control unit for a hybrid vehicle that has a canister that is configured to adsorb evaporative fuel generated in a fuel tank of an internal combustion engine, and that is capable of driving a drive wheel even when the internal combustion engine is stopped, comprising: using an electric motor connected to the internal combustion engine to rotate the internal combustion engine when the internal combustion engine is stopped during operation of the vehicle and a prescribed set of conditions is satisfied (S21, S22); and, when the electric motor rotates the internal combustion engine, introducing the evaporative fuel adsorbed in the canister to an upstream side of an exhaust purification catalytic converter (41, 42) provided in an exhaust passage of the internal combustion engine, and causing the introduced evaporative fuel to be adsorbed by the exhaust purification catalytic converter as a reducing agent, characterized by: controlling an engine rotational speed of the internal combustion engine when the internal combustion engine is rotated by the electric motor to be lower than the engine rotational speed of the internal combustion engine when in a power generation mode, in which the internal combustion engine drives the electric motor as a generator such that the evaporative fuel is not discharged outside via the exhaust passage, wherein the internal combustion engine has a bypass passage (67, 69) capable of returning the introduced evaporative fuel from a downstream side of the exhaust purification catalytic converter to an intake passage of the internal combustion engine, a bypass valve (68, 70) configured to open and close the bypass passage is provided in the bypass passage, an HC detection unit configured to detect an amount of hydrocarbon is provided in the exhaust passage on the downstream side of the exhaust purification catalytic converter, and the opening degree of the bypass valve is controlled in accordance with the amount of hydrocarbon detected by the HC detection unit to recirculate the hydrocarbon on the downstream side of the exhaust purification catalytic converter to the intake passage. using an electric motor connected to the internal combustion engine to rotate the internal combustion engine when the internal combustion engine is stopped during operation of the vehicle and a prescribed set of conditions is satisfied (S21, S22); and, when the electric motor rotates the internal combustion engine, introducing the evaporative fuel adsorbed in the canister to an upstream side of an exhaust purification catalytic converter (41, 42) provided in an exhaust passage of the internal combustion engine, and causing the introduced evaporative fuel to be adsorbed by the exhaust purification catalytic converter as a reducing agent, controlling an engine rotational speed of the internal combustion engine when the internal combustion engine is rotated by the electric motor to be lower than the engine rotational speed of the internal combustion engine when in a power generation mode, in which the internal combustion engine drives the electric motor as a generator such that the evaporative fuel is not discharged outside via the exhaust passage, wherein the internal combustion engine has a bypass passage (67, 69) capable of returning the introduced evaporative fuel from a downstream side of the exhaust purification catalytic converter to an intake passage of the internal combustion engine, a bypass valve (68, 70) configured to open and close the bypass passage is provided in the bypass passage, an HC detection unit configured to detect an amount of hydrocarbon is provided in the exhaust passage on the downstream side of the exhaust purification catalytic converter, and the opening degree of the bypass valve is controlled in accordance with the amount of hydrocarbon detected by the HC detection unit to recirculate the hydrocarbon on the downstream side of the exhaust purification catalytic converter to the intake passage.