A data processing apparatus according to the present invention is capable of writing video and/or audio data to a storage medium. The data processing apparatus includes: a power controller for controlling powering on or off; a signal processing circuit for generating data; and a drive section for writing the generated data to the storage medium. In response to a powering-off instruction, the power controller stops supplying power to the drive section but continues to supply power to the signal processing circuit and the power controller itself. Since hardware elements remain energized, they do not need to perform initialization operations when the apparatus is powered on. Similarly, corresponding software elements are also in an operable state, and therefore do not need to perform initialization processes. Therefore, the signal processing circuit can immediately start processing thereafter.