Abstract: A semiconductor storage device includes a plurality of planes, the planes including a first plane and a second plane, an interface circuit configured to receive and transmit control signals for the planes, and a control circuit configured to control the planes based on the control signals. While a first operation that includes multiple loops of a high voltage operation and a verify operation is being performed by the first plane, the control circuit controls the second plane to perform a second operation during at least one period in which the verify operation is performed by the first plane.