Abstract: There is provided a technique that includes abnormality detecting by picking up a sound generated from a transfer configured to operate in a vacuum and transport a substrate in a vacuum transfer chamber and compare the sound information with a preset threshold value to detect an abnormality of the transfer. The transfer includes a gas-filled container arranged in the vacuum transfer chamber and filled with a gas and a microphone installed inside the gas-filled container.

Abstract: An electronic timer having two electromagnetic relays is disclosed. The two electromagnetic relays are mounted on an insulating base plate. The electronic timer further comprises a delay circuit. At least one of the two electromagnetic relays is connected to an external power supply through the delay circuit. These two electromagnetic relays may be connected in such a manner that when connected with an external power supply, one of them is operated instantaneously while the other is actuated after a delay time, or in such a manner that both of them are simultaneously operated after a predetermined delay time, or in such a manner that they are operated after different delay times.

Abstract: An abnormal voltage detection circuit includes a series circuit of a resistor and a capacitor coupled across a power source by means of a switch, an inverter with the input terminal coupled to the junction of the resistor and capacitor, and an R-S flip-flop circuit with the set and reset input terminals coupled to the output terminal of the inverter and a manual switch respectively. The R-S flip-flop circuit is set by a first threshold voltage lower than the threshold voltage of the inverter, and reset by a second threshold voltage higher than the threshold voltage of the inverter.