A semiconductor laser device with a quantum-dot structure allowing for improvement of its high-temperature operation characteristics is provided. The semiconductor laser device has an active-layer structure including one or more active layers. Each active layer has a quantum-dot structure. The quantum-dot structure includes: an island-shaped crystal; a lateral potential barrier layer that at least partially embeds the perimeter of the island-shaped crystal; and an upper crystal layer that covers both an upper end part of the island-shaped crystal and the lateral potential barrier layer. A first bandgap of the lateral potential barrier layer is larger than a second bandgap of the upper crystal layer.