PURPOSE: To make the pulling-put of a sink drawer and an opening operation of a hinged door achievable so easily and positively by installing a rocking shaft center of a doorin an opening position after retracting a rockingly positioned door to the opposite side to an opening more than an opening inner circumferential surface.

CONSTITUTION: A hot-water supplying chamber is set up at the side of a passage B, and when it is applied to the gateway A, a frontage of this gateway A is formed into the same width as this chamber C. Next, as for a symmetrical pair of doors 2 being installed in this gateway A, both up and down frames of a circumferential frame 1 serve as a setting part, and are attached thereto in an opening out manner free of rocking on-off operation around a downward rocking shaft center X. At this time, the gateway A is fully opened along the passing direction, and this rocking shaft center is installed by way of retracting the rockingly positioned door 2 to the opposite side to an opening more than an opening inner circumferential surface (a). Then the door 2 is rockingly situated in the opening position, dispensing with any projection of the door 2 to the gateway A, and an overall width of the gateway A is used, thereby enabling it to open. With this constitution, a taking-in-and-out operation of a sink 3A in relation to the hot-water supplying chamber C is performed in a state that the door 2 is attached, thus maintenance can be done so easily.