A paper sheet storage device includes a storage space in which paper sheet is stored; a mounting table that is provided in the storage space and on which the paper sheet is accumulated and placed; a support base that supports the mounting table; a first lifting lowering mechanism that lifts and lowers the mounting table between a high position and a low position relative to the support base; and a second lifting lowering mechanism that lifts and lowers the support base in the storage space. The support base and the first lifting lowering mechanism are disposed within a projection area in which the mounting table is projected on a plane orthogonal to a lifting lowering direction in which the support base is lifted and lowered by the second lifting lowering mechanism.