A tape dispenser includes a main member, on which a tape roll mount, a cutter and a movable shield are provided, wherein the shield is moved to cover or expose the cutter, and at least a flexible arm is projected from the shield directly. The flexible arm has a suspended end urging a bottom wall of the main member. The flexible arm is compressed when the shield is moved to expose the cutter, and the compressed flexible arm may return the shield to cover the cutter automatically.