A vehicular antenna device includes an antenna unit transmitting and receiving various electromagnetic waves or signals, an antenna cover configured to cover the antenna unit, and a pad configured to be attached to an inner peripheral surface of the antenna cover. The antenna unit is configured to be attached to the antenna cover with the pad disposed therebetween. The pad includes a plurality of pressure ribs formed in an inner surface of a peripheral wall thereof. The pressure ribs are configured to be pressed by the antenna unit being attached to the antenna cover in a condition in which the pad is partially displaced from a predetermined position relative to the antenna cover before the antenna unit is attached to the antenna cover.