Electronic device capable of controlling power supply to storage device

An electronic device comprising:

• a storage device;
• and
• a control device comprising a processor and functioning, through the processor executing a control program, as a controller that controls an operation of the storage device,
• wherein the controller sets the electronic device to an operation mode selected from at least a first mode where a power supply to the storage device is allowed to be on and a second mode where the power supply to the storage device is off,
• upon occurrence of a predetermined event leading to transition from the second mode to the first mode when the operation mode of the electronic device is the second mode, the controller allows the operation mode to transition from the second mode to the first mode,
• when, during operation of the electronic device in the first mode, a waiting period for which processing accompanying the event remains unexecuted reaches a predetermined threshold value, the controller allows the operation mode to transition from the first mode to the second mode,
• when the controller allows the operation mode to transition from the second mode to the first mode and determines that an operating period of the operation in the second mode just previous to transition to the first mode has exceeded a predetermined criterion threshold, the controller sets the threshold value to a predetermined value serving as a first reference period, and
• when the controller allows the operation mode to transition from the second mode to the first mode and determines that the operating period of the operation in the second mode just previous to the transition to the first mode is not more than the criterion threshold, the controller sets the threshold value to a predetermined value serving as a second reference period longer than the first reference period.