To provide a holder in which an article can be held firmly and for which a high dimensional accuracy is not needed, and to provide a packaging container in which an article can be stored simply.

A pair of plate-like members having flexibility 20a, 20b are opposed and the circumferences of the plate-like members are connected to each other, wherein holes 12, 13 provided on the plate-like members, holding membranes 14, 15 having elasticity and covering the holes 12 and 13, one or a plurality of openings 18, 19 provided on the circumference of the pair of plate-like members 20a, 20b and a pair of folding pieces 21a, 22a and 21b, 22b provided on the openings 18, 19, are equipped. The article A is put between the plate-like members 20a and 20b from the openings 18, 19 and is held by tensile force of the holding membranes 14, 15 and by folding the pair of folding pieces 21a, 22a and 21b, 22b, deflection of the openings 18, 19 is regulated and the intervals of the openings 18, 19 are kept constant.