A storage device includes a first conductor, a second conductor, a variable resistance layer, a first portion, and a second portion. The variable resistance layer connects with the first conductor or the second conductor. The first portion is provided between the first conductor and the second conductor, and has a first threshold voltage value at which the resistance value changes. The second portion is provided between the first conductor and the first portion and/or between the second conductor and the first portion, and has a second threshold voltage value at which the resistance value changes and which is higher than the first threshold voltage value.