The invention provides a job processing apparatus and a method of controlling the same. The job processing apparatus that performs job processing by using power supplied from a first power supply and a second power supply includes a receiving unit that receives a job; a calculating unit that calculates an amount of power consumed to process the received job; a determining unit that determines whether the received job is executable with a first amount of power that can be supplied from the first power supply and the calculated amount of power; and a control unit that performs control so that the job is processed with the power supplied from the first power supply if the determining unit determines that the job is executable with the first amount of power and the job is processed with the power supplied from the second power supply if the determining unit determines that the job is not executable with the first amount of power.