Many kinds of input interface using biological signals such as EMG, EEG and breathing etc. have been studied in recent years. It is important for input devices to be easily used for elderly and disable persons. We are now investigating input interface by using biological signals occurring by blink and eyelid closing/opening. This paper presents the experimental results of the characteristics of signals by blink and eyelid closing/opening. The success ratio by using eyelid closing/opening signals is examined as a trigger of command. And it is shown that the proposed method can be applicable as trigger signal for operating equipment.