PROBLEM TO BE SOLVED: To prevent liquid droplets from adhering to each other and from adhering to a gutter when passing liquid droplets into a cooling medium flowing in the gutter.SOLUTION: A gutter 4 is bent in a V shape in flank view in the middle in the longitudinal direction, and the relative angle is θ. With this, in a relation with the installation surface of a device, inclination in an upstream part of the gutter 4 is relatively sharp, and on the other hand, inclination in a downstream part after bending is relatively gradual. Owing to the structure, the flow of low-temperature liquid gas is fast in the upstream part of the gutter 4 so as to prevent liquid droplets from adhering to each other, and on the other hand, the flow of low-temperature liquid gas is slow in the downstream part so as to secure a cooling action for a prescribed time or more by a short length. Furthermore, a flow width is gradually narrowed in the downstream part of the gutter 4, and thereby, low-temperature liquid gas is hardly discharged from the gutter 4 so as to raise the liquid surface of low-temperature liquid gas in the entire gutter 4, and the depth of low-temperature liquid gas in a drip position with a dripping nozzle becomes a desired value or more.SELECTED DRAWING: Figure 2
