To provide a tin plating solution having uniformity of through-hole plating, uniformity of film thickness distribution and no burn deposits even. In one aspect, a nebulizer is pressure sensitive so that nebulization is coordinated with a breathing cycle of the patient. Each measuring tubes opens with an inlet-side, measuring tube end into one of the flow openings of the flow divider and with an outlet-side, measuring tube end into one the flow openings of the flow divider. Only the dispersion-treated solution passing through the filter is fed to a product tank through a liquid discharge port. When a still image is displayed by utilizing a ferroelectric element as a nonvolatile memory element and storing a signal, writing is not required per frame. The advantage of the inventive plate is that an airtight heat exchanger cassette can be obtained in an easy and cost-effective way.