To minimize arm influence given to the inside and outside of a machine device and an exposure device through vibrations accompanying an earthquake by utilizing the output of a detecting means for detecting the earthquake to fix a main section to a foundation section.

An exposure device 1 has a foundation section 2 and a main section 4 attached to its upper part through a vibration control pad 3. A fixing arm 5 is attached to the surface plate 4F of the main section 4, and a fastening part 6 is fixed to the foundation section 2. The main section 4 can be fixed to the foundation section 2 by mutually engaging the fixing arm 5 and the fastening part 6. In addition, the exposure device 1 has a receiver to receive an earthquake warning signal. This signal is transmitted in the case of the occurrence of the earthquake detected to be above a fixed level where it is required to shut down the exposure device 1 and to actuate the fastening part 6, and the tip of a vertical part of the fixing arm 5 is sandwichedly fixed by the function of the fastening part 6. Thus the main section 4 can be prevented from falling from a machine device in the case of the occurrence of the earthquake.