To obtain a mattress facilitating washing with hot water and sterilization by steam and maintaining a sanitary state by gathering many plastic bending wires given anti-bacterial treatment in a three-dimensional net state and providing a washing pipe and a ventilator or a hole part capable of mounting a deodorizer, etc., inside of it.

The mattress 1 is constituted by gathering the many bending wires made of plastic such as polypropylene given anti-bacterial treatment in the state of a three-dimensional net and hole parts 3 of a necessary diameter are formed inside of it. Each hole part 3 can insert a washing pipe, an air duct, etc., through it and a bag, etc., housing a deodorizer, etc., is inserted to it. In addition cuts 4 are provided at proper places to bend following the reclining operation of a bed main body. At the time of washing, the washing pipe, etc., is inserted through the part 3 to eject hot water, steam, etc., from this to wash the mattress 1 with hot water from inside or to sterilize with steam to easily secure a satisfactory sanitary state.