The invention provides a surgical instrument for scope-assisted surgery which has a temporary liquid-pooling function (first function), a function of ensuring a physical space and visual field for the surgery (second function) and an organ-protecting function (third function) and an instrument for inserting the same into the body. The surgical instrument for scope-assisted surgery as described above is an organ spacer (10) characterized by comprising a liquid holder unit (1) made of a porous and flexible material having a temporary liquid-pooling property and a shape retention property. The instrument for insertion into the body as described above comprises a tubular housing in which the organ spacer for scope-assisted surgery as described above can be stored.