No. You should never leave your baby alone in a high chair, as they are designed for feeding and eating, not for watching your baby. Even though the baby will be strapped in with a harness, babies are crafty little troublemakers. Inevitably, they will find a way to get hurt like grabbing on to the table and toppling over.  Always stay in the room with your baby when they are in a high chair. Although, it is a safe place to keep them while you cook so long as you keep the far away from the counter and stove.