In a first punching mode, a control portion displaces a support member from a first-path-side end side to a second-path-side end side, and causes a first punching portion on the first-path-side end side to operate in a state where the support member has reached a first target position. In a second punching mode, the control portion displaces the support member from the second-path-side end side to the first-path-side end side, and causes a second punching portion on the second-path-side end side to operate in a state where the support member has reached a second target position. The first and second target positions are based on positions of the support member at points of time when edges on the first-path-side end side and the second-path-side end side are detected by the first sheet sensor and the second sheet sensor, respectively.