A single facer for producing a single-faced corrugated paperboard by forming a corrugated medium and gluing a linerboard onto the corrugated medium, comprising: a pair of corrugating rolls (23, 24) configured to form the corrugated medium; a processing roll (30, 44) configured to be brought into contact with a specific one of the corrugating rolls (23, 24) through the corrugated medium and the linerboard or through the corrugated medium so as to perform a given processing; a supporting mechanism (27, 28, 40, 42) supporting the processing roll (30, 44) in such a manner as to allow a gap between the specific corrugating roll (23, 24) and the processing roll (30, 44) to be changed, at least a part of the supporting mechanism (27, 28, 40, 42) being configured to be movable to cause a change in the gap; a pressing actuator section (32, 33, 47, 48) configured to press the processing roll (30, 44) against the specific corrugating roll (23, 24) through the corrugated medium and the linerboard or through the corrugated medium; a restricting mechanism (115, 135, 215, 235) comprising a restriction member (118, 121, 218, 221) disposed in contactable relation to the movable part of the supporting mechanism (27, 28, 40, 42), the restricting mechanism (115, 135, 215, 235) being configured to allow the restriction member (118, 121, 218, 221) to be displaced with respect to the movable part of the supporting mechanism (27, 28, 40, 42); a motor (120, 140, 220, 240) configured to be driven so as to displace the restriction member (118, 121, 218, 221); and a control section for controlling the drive of the motor (120, 140, 220, 240), the control section being configured to execute a first control processing of driving the motor (120, 140, 220, 240) until a magnitude of vibration occurring in the processing roll (30, 44) during the formation of the corrugated medium through the corrugating rolls (23, 24) is reduced to a given value; characterized in that the single facer further comprises: a detection device configured to detect vibration occurring in the processing roll (30, 44) during the formation of the corrugated medium through the corrugating rolls (23, 24), the detection device detecting a rotation torque of the motor (120, 140, 220, 240), as the vibration occurring in the processing roll (30, 44); wherein the control section is configured to execute the first control processing in such a manner as to drive the motor (120, 140, 220, 240) until a state in which the rotation torque of the motor (120, 140, 220, 240) is increased to a given torque continues for a given time. a pair of corrugating rolls (23, 24) configured to form the corrugated medium; a processing roll (30, 44) configured to be brought into contact with a specific one of the corrugating rolls (23, 24) through the corrugated medium and the linerboard or through the corrugated medium so as to perform a given processing; a supporting mechanism (27, 28, 40, 42) supporting the processing roll (30, 44) in such a manner as to allow a gap between the specific corrugating roll (23, 24) and the processing roll (30, 44) to be changed, at least a part of the supporting mechanism (27, 28, 40, 42) being configured to be movable to cause a change in the gap; a pressing actuator section (32, 33, 47, 48) configured to press the processing roll (30, 44) against the specific corrugating roll (23, 24) through the corrugated medium and the linerboard or through the corrugated medium; a restricting mechanism (115, 135, 215, 235) comprising a restriction member (118, 121, 218, 221) disposed in contactable relation to the movable part of the supporting mechanism (27, 28, 40, 42), the restricting mechanism (115, 135, 215, 235) being configured to allow the restriction member (118, 121, 218, 221) to be displaced with respect to the movable part of the supporting mechanism (27, 28, 40, 42); a motor (120, 140, 220, 240) configured to be driven so as to displace the restriction member (118, 121, 218, 221); and a control section for controlling the drive of the motor (120, 140, 220, 240), the control section being configured to execute a first control processing of driving the motor (120, 140, 220, 240) until a magnitude of vibration occurring in the processing roll (30, 44) during the formation of the corrugated medium through the corrugating rolls (23, 24) is reduced to a given value; characterized in that the single facer further comprises: a detection device configured to detect vibration occurring in the processing roll (30, 44) during the formation of the corrugated medium through the corrugating rolls (23, 24), the detection device detecting a rotation torque of the motor (120, 140, 220, 240), as the vibration occurring in the processing roll (30, 44); wherein the control section is configured to execute the first control processing in such a manner as to drive the motor (120, 140, 220, 240) until a state in which the rotation torque of the motor (120, 140, 220, 240) is increased to a given torque continues for a given time. a detection device configured to detect vibration occurring in the processing roll (30, 44) during the formation of the corrugated medium through the corrugating rolls (23, 24), the detection device detecting a rotation torque of the motor (120, 140, 220, 240), as the vibration occurring in the processing roll (30, 44); wherein the control section is configured to execute the first control processing in such a manner as to drive the motor (120, 140, 220, 240) until a state in which the rotation torque of the motor (120, 140, 220, 240) is increased to a given torque continues for a given time.