Die for producing receptacles substantially impervious to liquid by bonding a bottom plate to an apertured receptacle made from a uni-directionally shrinkable thermoplastic resin foam sheet into an apertured receptacle having a flat annular portion provided in continuous with the lower end thereof comprises a female mold and a male mold defining when they are clamped together clearnaces therebetween whose thickness is less than that of the peripheral side wall of the apertured receptacle at the portion corresponding to the peripheral side wall and less than those of the annular portion of the apertured receptacle and the bottom plate at the portion corresponding to the bottom of the resulting receptacle, and at least one annular ridge having a height 50 - 90 % of the thickness of the clearance at the bottom and being integrally provided either on the inner surface of the female mold or the outer surface of the male mold at the portions against which the annular portion of the apertured receptacle is abutted.