To efficiently carry out boiling with reduced labor by arranging a raised bottom part in a part of on the inside of a sink and mounting a cooker on the bottom face of the raised bottom part freely removably.

In boiling, a pot 8 is placed on an electromagnetic cooker 5 and water is directly supplied from a tap 6 of a water service. Then, the water inside the pot 8 is boiled by means of the electromagnetic cooker 5 for boiling vegetables and the like. In this process, a raised bottom part 4 is arranged higher than a general part 3, so that water flow into the electromagnetic cooker 5 is restricted even when washing is carried out inside a sink 2, and water penetration is prevented. After the vegetables and the like are boiled, the pot 8 is lifted and its content is directly poured into a sieve and the like placed in the sink 2 so as to be drained. In this way, boiling is carried out efficiently with less labor. As the electromagnetic cooker 5 is only placed on the raised bottom part 4, the cooker 5 can be taken away so as to be used in another place such as a dining table for one-pot cooking, so that the single electromagnetic cooker 5 can be used in other places and usability is improved.