A hybrid vehicle that includes an internal combustion engine that outputs power for travel; a motor to and from which power for travel is input and output; and a secondary battery that transmits and receives electric power to and from the motor, wherein the hybrid vehicle travels using only the power input to and output from the motor in an electric-powered travel mode, and the hybrid vehicle travels using the power output from the internal combustion engine and the power input to and output from the motor in a hybrid travel mode, the hybrid vehicle characterized by comprising: a mode setting portion that sets an execution travel mode to one of two travel modes including an electric-powered travel priority mode where the hybrid vehicle travels with priority being given to the electric-powered travel mode over the hybrid travel mode, and a hybrid travel priority mode where the hybrid vehicle travels with priority being given to the hybrid travel mode over the electric-powered travel mode; a control portion that, when the execution travel mode is switched by the mode setting portion while the internal combustion engine is being operated, controls the internal combustion engine and the motor so that charging/discharging electric power for charging or discharging the secondary battery is gradually changed and the hybrid vehicle travels in the switched execution travel mode; and a charge ratio calculation portion that calculates a charge ratio that is a ratio of an amount of electricity stored in the secondary battery to an entire capacity of the secondary battery, based on a state of the secondary battery, wherein the control portion sets engine required power that is to be output from the internal combustion engine, based on a sum of travel power that is required for travel based on an accelerator operation, and charging/discharging required power that is required for charging or discharging the secondary battery based on the calculated charge ratio, and the control portion controls the internal combustion engine and the motor so that the set engine required power is output from the internal combustion engine under a predetermined restriction imposed on an operation of the internal combustion engine and the hybrid vehicle travels with the travel power; and when the execution travel mode is switched while the engine is being operated, the control portion sets and controls the charging/discharging required power so that the charging/discharging required power is gradually changed to decrease a difference in the charging/discharging required power due to switching of the execution travel mode. a mode setting portion that sets an execution travel mode to one of two travel modes including an electric-powered travel priority mode where the hybrid vehicle travels with priority being given to the electric-powered travel mode over the hybrid travel mode, and a hybrid travel priority mode where the hybrid vehicle travels with priority being given to the hybrid travel mode over the electric-powered travel mode; a control portion that, when the execution travel mode is switched by the mode setting portion while the internal combustion engine is being operated, controls the internal combustion engine and the motor so that charging/discharging electric power for charging or discharging the secondary battery is gradually changed and the hybrid vehicle travels in the switched execution travel mode; and a charge ratio calculation portion that calculates a charge ratio that is a ratio of an amount of electricity stored in the secondary battery to an entire capacity of the secondary battery, based on a state of the secondary battery, wherein the control portion sets engine required power that is to be output from the internal combustion engine, based on a sum of travel power that is required for travel based on an accelerator operation, and charging/discharging required power that is required for charging or discharging the secondary battery based on the calculated charge ratio, and the control portion controls the internal combustion engine and the motor so that the set engine required power is output from the internal combustion engine under a predetermined restriction imposed on an operation of the internal combustion engine and the hybrid vehicle travels with the travel power; and when the execution travel mode is switched while the engine is being operated, the control portion sets and controls the charging/discharging required power so that the charging/discharging required power is gradually changed to decrease a difference in the charging/discharging required power due to switching of the execution travel mode.