Preheat oven to 450°F. Line rimmed baking sheet with aluminum foil.
Spread beans on baking sheet. Drizzle with oil and sprinkle with salt and pepper. Using hands, toss to coat evenly. Distribute beans in even layer. Roast 10 minutes.
Using tongs, turn green beans and redistribute evenly. Continue roasting until beans are dark golden brown in spots and have started to shrivel, 10 to 12 minutes longer.