A hybrid vehicle comprising: a motor for generating power to drive the vehicle; an internal combustion engine configured to be capable of outputting power to drive the vehicle independently of said motor; a main power storage device; an electric power feeding line for supplying electric power to an inverter that controls and drives said motor; a first voltage converter provided between said electric power feeding line and said main power storage device and configured to convert voltage bidirectionally; a plurality of sub power storage devices (BB1, BB2) provided in parallel to each other; a second voltage converter provided between said plurality of sub power storage devices and said electric power feeding line and configured to convert voltage between one of said plurality of sub power storage devices and said electric power feeding line bidirectionally; a connection unit provided between said plurality of sub power storage devices and said second voltage converter and configured to selectively connect a selected sub power storage device among said plurality of sub power storage devices to said second voltage converter; a switching control device configured to control selective connection between said plurality of sub power storage devices and said second voltage converter; and a traveling control unit for performing a process of starting said internal combustion engine when stopped and a process of stopping said internal combustion engine when operating, in accordance with a driving power distribution control for dividing and thus assigning a total required power (Pttl) for hybrid vehicle to power output from said motor and power output from said internal combustion engine, and characterized in that said traveling control unit is configured so as to prohibit said process for starting said internal combustion engine and said process for stopping said internal combustion engine, while a process for switching a connection between said plurality of sub power storage devices and said second voltage converter is being performed. a motor for generating power to drive the vehicle; an internal combustion engine configured to be capable of outputting power to drive the vehicle independently of said motor; a main power storage device; an electric power feeding line for supplying electric power to an inverter that controls and drives said motor; a first voltage converter provided between said electric power feeding line and said main power storage device and configured to convert voltage bidirectionally; a plurality of sub power storage devices (BB1, BB2) provided in parallel to each other; a second voltage converter provided between said plurality of sub power storage devices and said electric power feeding line and configured to convert voltage between one of said plurality of sub power storage devices and said electric power feeding line bidirectionally; a connection unit provided between said plurality of sub power storage devices and said second voltage converter and configured to selectively connect a selected sub power storage device among said plurality of sub power storage devices to said second voltage converter; a switching control device configured to control selective connection between said plurality of sub power storage devices and said second voltage converter; and a traveling control unit for performing a process of starting said internal combustion engine when stopped and a process of stopping said internal combustion engine when operating, in accordance with a driving power distribution control for dividing and thus assigning a total required power (Pttl) for hybrid vehicle to power output from said motor and power output from said internal combustion engine, and characterized in that said traveling control unit is configured so as to prohibit said process for starting said internal combustion engine and said process for stopping said internal combustion engine, while a process for switching a connection between said plurality of sub power storage devices and said second voltage converter is being performed.