Operation members of the operation unit 70 are respectively assigned appropriate functions for each scene by, for example, selectively operating various functional icons displayed on the display unit 28, so as to act as various functional buttons. Examples of the functional buttons include an end button, a return button, an image feeding button, a jump button, a narrowing-down button, and an attribute change button. For example, if a menu button is pressed, a menu screen for enabling various settings to be performed is displayed on the display unit 28. The user can intuitively perform various settings using the menu screen displayed on the display unit 28, a four-direction (up, down, left, and right) button, and a SET button. In addition, the touch panel 70a is also included in the operation unit 70.
A power supply control unit 81 includes, for example, a battery detecting circuit, a direct current (DC)-DC converter, and a switch circuit for switching a block to be supplied with power. The power supply control unit 81 detects whether or not a battery is attached, the type of the battery, and remaining battery capacity. In addition, the power supply control unit 81 controls, based on the detection result and an instruction from the system control unit 50, the DC-DC converter to supply necessary voltage to components including the recording medium 200 for necessary time period. A power source unit 30 includes a primary battery such as an alkaline battery and a lithium battery, a secondary battery such as a nickel-cadmium (NiCd) battery, a nickel-metal hydride (NiMH) battery, a lithium (Li) battery, and an alternating current (AC) adapter.