It is intended to realize a signal input method which makes it possible to add another method to an existing method later in a simple manner as well as an opening/closing controller which employs two methods and can be constructed by adding another method to an existing method in a simple manner.A signal processing circuit (5) is inserted in an auto signal path of a control circuit (1) which performs opening/closing control with a pinch preventing function on the basis of an auto signal (AUTO), a close signal (UP), and an open signal (DOWN) which are input via respective signal paths. The auto signal and a detection signal of an additional pinch sensor are input to the control circuit via the signal processing circuit in the form of serial signals.