Mop and mop wringer

A mop having a sponge mop pad is effective for cleaning in a hospital for avoidance of internal infection. In a conventional sponge mop, for washing off dust and dirt sticking to the mop after used for the cleaning, spring force has been used for folding the sponge mop pad at the middle position thereof to squeeze off the water contained in the mop by compression force. This requires a large force and workers, especially women workers, had a difficulty in the cleaning work. In the present invention, the mop having the sponge mop pad comprises a projection and the mop squeezer comprises an insert member into which the projection is inserted. By the principle of lever, the sponge mop pad is easily squeezed by homogenous compression force and predetermined water content of the mop, after squeezed, can be realized.