A control device includes: a memory controller configured to output a control signal to a nonvolatile memory in response to a write request from a processor; a voltage monitoring portion configured to monitor an input voltage supplied from an input power supply; a mask signal generating portion configured to generate and output a mask signal when the voltage monitoring portion determines that the input voltage has decreased; and a masking portion configured to apply, when receiving the mask signal outputted from the mask signal generating portion, a masking processing to the control signal outputted from the memory controller to the nonvolatile memory. When the voltage monitoring portion determines that the input voltage has decreased, and the data is being written to the nonvolatile memory, then the mask signal generating portion outputs the mask signal after the completion of the data writing.