The probe unit includes probe groups of two or more contact probes to be in contact with one electrode of a contact target body on a side of one end in a longitudinal direction and the respective contact probes are to be in contact with separate electrodes of a board on a side of another end. The contact probe includes an end portion arranged on the side of one end, having nail portions in a tapered end shape, and brought into contact with the one electrode at the nail portions; a second contact unit arranged on the side of another end, and to be in contact with a corresponding electrode of the board; and a coil spring arranged between the end portion and the second contact unit, and biasing the end portion and the second contact unit.