An antenna substrate comprising: a cap substrate including a first insulating layer and a plurality of first antenna conductors arranged in vertical and horizontal directions on upper and lower surfaces of the first insulating layer, the plurality of first antenna conductors being positioned opposite to each other with the first insulating layer therebetween; a frame substrate including a second insulating layer and a plurality of openings located in the second insulating layer, each of the plurality of openings having an outer periphery that surrounds an individual or a collective number of outer peripheries of the plurality of first antenna conductors in a top view; a base substrate including a third insulating layer and a plurality of second antenna conductors located on an upper surface of the third insulating layer; a first adhesive material provided between a lower surface of the first insulating layer and an upper surface of the second insulating layer in a region other than a region where the opening is located, the first adhesive material adhering the first insulating layer and the second insulating layer to each other; and a second adhesive material provided between a lower surface of the second insulating layer and the upper surface of the third insulating layer in a region other than a region where the opening is located, the second adhesive material adhering the second insulating layer and the third insulating layer to each other, characterized in that: each of the first adhesive material and the second adhesive material at least includes a first bonding member and a second bonding member at a different position than the first bonding member, the first bonding member being located outside a region where the first antenna conductor is disposed, the second bonding member being partially in contact with the first bonding member, the second bonding member having an adhesive strength to the second insulating layer greater than that of the first bonding member. a cap substrate including a first insulating layer and a plurality of first antenna conductors arranged in vertical and horizontal directions on upper and lower surfaces of the first insulating layer, the plurality of first antenna conductors being positioned opposite to each other with the first insulating layer therebetween; a frame substrate including a second insulating layer and a plurality of openings located in the second insulating layer, each of the plurality of openings having an outer periphery that surrounds an individual or a collective number of outer peripheries of the plurality of first antenna conductors in a top view; a base substrate including a third insulating layer and a plurality of second antenna conductors located on an upper surface of the third insulating layer; a first adhesive material provided between a lower surface of the first insulating layer and an upper surface of the second insulating layer in a region other than a region where the opening is located, the first adhesive material adhering the first insulating layer and the second insulating layer to each other; and a second adhesive material provided between a lower surface of the second insulating layer and the upper surface of the third insulating layer in a region other than a region where the opening is located, the second adhesive material adhering the second insulating layer and the third insulating layer to each other, characterized in that: each of the first adhesive material and the second adhesive material at least includes a first bonding member and a second bonding member at a different position than the first bonding member, the first bonding member being located outside a region where the first antenna conductor is disposed, the second bonding member being partially in contact with the first bonding member, the second bonding member having an adhesive strength to the second insulating layer greater than that of the first bonding member.