Patent ID: 8621783

Claim:
A hollow pot comprising: a pot unit having an inner layer with a reception area defined therein, an outer layer supporting the inner layer, and a space defined between the inner and outer layers, a through hole located in communication between the reception area and the space, a water introducing unit located in communication between the space and outside of the pot unit, a seal unit sealing the water introducing unit so as to form the space, a transparent window located at the outer layer of the pot unit and communicating with the space at two positions so that the transparent window communicates with the space, the outer layer of the pot unit having a notch which has a top end and a bottom end communicating with the space, the transparent window being engaged with the notch and communicating with the space, a level of liquid in the space being observed via the transparent window, the transparent window having a transparent member, a seal member and a third member, the transparent member located on the outer layer of the pot unit by the third member, the seal member located between transparent member and the outer layer or the notch so that a room between the space, the notch and the transparent member is an air-tight room.