An information processor having a plurality of operating modes differing in power consumption and capable of changing the operating mode according to the amount of processing has periodic switching detection means of performing detection as to whether the information processor is periodically switching from a low-power-consumption operating mode in which the power consumption is lower to a high-power-consumption operating mode in which the power consumption is higher in the plurality of operating modes, and operating mode changing means of changing the operating modes between which the information processor switches to a combination of the operating modes such that the difference between the power consumptions is reduced relative to that at the time of switching between the low-power-consumption operating mode and the high-power-consumption operating mode if the switching cycle detected by the periodic switching detection means is shorter than a set cycle determined in advance.