A semiconductor storage device includes first and second chips. The first chip has first bonding electrodes on a first surface. The second chip has second bonding electrodes on a second surface. The first surface is bonded to the second surface and the first bonding electrodes are electrically connected to the second bonding electrodes. One of the first and second chips has a first bonding pad electrode connectable to a bonding wire for data input/output. A first one of the first bonding electrodes is electrically connected to the first bonding pad electrode. The first chip has, on the first surface, a first insulating layer surrounding the first one of the first bonding electrodes and a second insulating layer that is farther from the first one of the first bonding electrodes than the first insulating layer and formed of a material different from that of the first insulating layer.