An opening and closing apparatus is disclosed. The opening and closing apparatus includes an opening and closing body, a capacitance sensor, and a sensor support member. The dynamic capacitance sensor has a conductive sensor electrode, and outputs a detection signal that corresponds to the capacitance between the sensor electrode and a conductive object located close to the sensor electrode. The sensor support member includes a guard electrode, a holding portion, an attaching portion, and a conductive reinforcing member. The reinforcing member is embedded in the main body. At least a part of the reinforcing member is embedded in the guard electrode such that the reinforcing member is integrated with the guard electrode.