A stereolithography device having a trough (2) for accommodating free-flowing, photopolymerizable material, a construction platform (4) suspended above the trough bottom on a lifting unit (6), and having a heating unit for heating the photopolymerizable material in the trough. The heating unit has a transparent, electrically conductive layer (33), which covers the entire area of at least the exposure region above the trough bottom, and which is provided outside the exposure region on opposing sides of the layer with electrical contacts (20) extended over the opposing sides, which are connected to a controlled electrical supplier to enable heating of the entire area of photopolymerizable material above the trough bottom in the exposure region by current flow through the layer.