The present invention is to form a new desirable silicon nitride film of lower dielectric constant even by using common gases. In the warm-up phase, the f002_hor is selected as fundamental frequency of the AM, or an AM is dispensed with. When the liquid achieves a substantially steady flow rate, the flow rate passing into the pipeline is recorded. Each pixel may also include a readout circuit which may include a reset transistor, a charge transfer switch transistor, source follower amplifier, and pixel select transistor.