Provided are a pellicle for lithography which can prevent a haze from being generated on a photomask even if a short wave length laser such as an ArF excimer laser is used for a long period of time, and a method for producing a pellicle film to be attached to the pellicle for lithography. A pair of electrodes sandwiches the light diffusion layer, an applying unit generates and applies a variable voltage to the pair of electrodes, and a voltage changing unit varies the voltage generated by the applying unit. The method also includes isomerizing the para-xylene depleted raffinate. The display pattern of standard text character andor hand entered characters can be changed by the user. The personal computer controls the plant equipment through a wireless transceiver and a network, and transmits therethrough information signals of on-site operation of the plant equipment to enable a display device and a soundvoice output device provided in the central control room.