Abstract: Provided is a device that facilitates a sample to enter a sample measurement channel in which measuring electrodes are arranged. A device used in measurement of tunnel current includes: a base material; a channel formed in the base material; and a pair of measuring electrodes for measuring tunnel current occurring when a sample passes between the pair of measuring electrodes. The channel includes a sample supply channel, a sample measurement channel in which the measuring electrodes are arranged, a first taper channel arranged between the sample supply channel and the sample measurement channel and having a channel width that decreases from the sample supply channel to the sample measurement channel, and a sample collection channel used for collecting a sample that passed through the sample measurement channel. The width of a connection part between the first taper channel and the sample measurement channel is 20 nm to 200 nm.