A polymerization apparatus according to one embodiment of the present invention comprises a photoirradiator and a polymerization vessel. The photoirradiator comprises a first housing and a light source assembly. The first housing comprises a light source chamber defined by cylindrical side walls, a ceiling, and a floor comprising a light-transmissive window. The light source assembly comprises a substrate having a light-emitting surface on which a plurality of light-emitting diodes are disposed in a prescribed pattern and a heat-dissipating surface to which a heat sink is joined, and the light source assembly is disposed within the light source chamber so that the light-emitting surface faces the light-transmissive window. The polymerization vessel comprises a polymerization cup and a second housing. The polymerization cup has a frustoconical or substantially frustoconical shape that opens upward and increases in diameter upward, and is capable of containing a target material therein. The second housing is a closed-bottom cylindrical or box-shaped housing having an opening at the apex thereof, the polymerization cup being detachably contained via said opening. In this polymerization apparatus, the interior of the polymerization cup of the polymerization vessel is irradiated with light that has been emitted by the plurality of light-emitting diodes of the photoirradiator and that has passed through the transmissive window.Un appareil de polymérisation selon un mode de réalisation de la présente invention comprend un photo-irradiateur et un récipient de polymérisation. Le photo-irradiateur comprend un premier boîtier et un ensemble source de lumière. Le premier boîtier comprend une chambre source de lumière définie par des parois latérales cylindriques, un plafond et un plancher comprenant une fenêtre transmettant la lumière. L'ensemble source de lumière comprend un substrat ayant une surface d'émission de lumière sur laquelle une pluralité de diodes électroluminescen
