A binding device includes a pressing member that has a first tooth, which forms unevenness in a recording material bundle, and a second tooth, which is paired with the first tooth and forms unevenness in the recording material bundle, and presses the recording material bundle with the recording material bundle sandwiched between the first tooth and the second tooth and a control unit that performs control such that pressing is released after a timing when a load on the pressing member decreases from start of pressing of the recording material bundle by the pressing member.