Preheat oven to 350°F. Place a roasting rack in a roasting pan, or rest a cooling rack on a baking sheet or large baking dish. Set aside.
Remove any giblets from the chicken (if there are any) and wash the bird inside and out, pat dry with paper towels.
Place the chicken, breast-side-down on the prepared pan. Place the lemon halves and rosemary sprigs into the chicken cavity. Sprinkle salt over the chicken.
Bake in preheated oven for 50-80 minutes, or until a thermometer reads 165°F when inserted in multiple fleshy parts of the chicken and all juices run clear. Remove from oven, cover with aluminum foil and let rest for at least 10 minutes before cutting.