A portable terminal device including a power switching means for carrying out switching between a normal power state in which power supply is not limited and a power conservation state in which the power supply is limited to reduce power consumption, the portable terminal device further comprising: a first state detection means configured to detect an acceleration value as vibrations applied to the portable terminal device; a second state detection means configured to detect a brightness value as a surface state of the portable terminal device or a peripheral state thereof; and a power control means which, in the case when a power supply to a predetermined peripheral device is limited, with switching being made by the power switching means to the power conservation state, is configured to remove the limit on the supply of power to the predetermined peripheral device when judged that the acceleration value detected by the first state detection means or a change amount thereof has satisfied a predetermined reference acceleration value and the brightness value detected by the second state detection means or a change amount thereof has satisfied a predetermined reference brightness value, wherein the predetermined peripheral device is a touch input means for inputting data in response to a touch operation, and the power control means is configured to remove the limit on the supply of power to the touch input means, and bring the touch input means to an inputtable state for accepting a touch operation when judged that the acceleration value detected by the first state detection means or the change amount thereof has satisfied the predetermined reference acceleration value and the brightness value detected by the second state detection means or the change amount thereof has satisfied the predetermined reference brightness value, wherein in the case when, upon removing the limit on the supply of power to the predetermined peripheral device when judged that the acceleration value detected by the first state detection means or the change amount thereof has satisfied the predetermined reference acceleration value and the brightness value detected by the second state detection means or the change amount thereof has satisfied the predetermined reference brightness value, the power control means judges whether or not a current time is within a predetermined time zone, and upon judging that the current time is within the predetermined time zone, removes the limit on the supply of power to the predetermined peripheral device, regardless of whether the brightness value detected by the second state detection means or the change amount thereof has satisfied the predetermined reference brightness value. a first state detection means configured to detect an acceleration value as vibrations applied to the portable terminal device; a second state detection means configured to detect a brightness value as a surface state of the portable terminal device or a peripheral state thereof; and a power control means which, in the case when a power supply to a predetermined peripheral device is limited, with switching being made by the power switching means to the power conservation state, is configured to remove the limit on the supply of power to the predetermined peripheral device when judged that the acceleration value detected by the first state detection means or a change amount thereof has satisfied a predetermined reference acceleration value and the brightness value detected by the second state detection means or a change amount thereof has satisfied a predetermined reference brightness value, wherein the predetermined peripheral device is a touch input means for inputting data in response to a touch operation, and the power control means is configured to remove the limit on the supply of power to the touch input means, and bring the touch input means to an inputtable state for accepting a touch operation when judged that the acceleration value detected by the first state detection means or the change amount thereof has satisfied the predetermined reference acceleration value and the brightness value detected by the second state detection means or the change amount thereof has satisfied the predetermined reference brightness value,