An embodiment of the present invention is an encased syringe in which a prefilled syringe is accommodated in a case. The prefilled syringe includes a cylindrical syringe body filled with a foamable material and a plunger pressed into the syringe body on one end side. The case includes a body accommodating part faulted to be depressed along the shape of the syringe body to accommodate the syringe body and a plunger accommodating part formed to be depressed along the shape of the plunger to accommodate the plunger. The length of the plunger accommodating part is smaller than the length of the plunger in an axial direction of the prefilled syringe.