To suppress an unstable operation of a device caused by filtering, an output selection unit is configured to acquire an unfiltered value representing an input signal (signal before filtering) stored in an input holding unit, a filtered value representing a signal acquired by filtering the input signal by a filtering unit, and a previous output value representing an output signal output at a previous time, select a middle value out of the filtered value, the unfiltered value, and the previous output value, and set the selected middle value as a current output value of an output signal.