A powder compression molding machine is configured such that a plurality of lower and upper punches 61, 41 are allowed to enter a plurality of through-die holes 31 provided in first and second molding die sections 32, 33 of a slide plate 3 in a compression molding zone 21 to compressively mold powder and the slide plate 3 is slid to push out compacts downward and collect them in compact discharge zones 22a, 22b. Even when powder is compressively molded at a low compression force into solids having high porosity, compacts can satisfactorily be molded and collected without crumblingness, the compacts having sufficient high porosity and being dissolvable in water or the like.