A length measurement device includes a tape portion (10) which is provided with a plurality of electrode pads (100a, 100b, 101a, 1010b, . . . ) arrayed thereon and is used in a state being wound around a measuring object, an impedance acquisition unit that selects any pair of electrode pads from a plurality of electrode pads and acquires electrical impedance between the pair of electrode pads, and a length calculation unit that calculates a length between the pair of electrode pads, based on a change in impedance of the pair of electrode pads.
