Multi-feed detection apparatus, sheet conveyance apparatus, and sheet processing apparatus

A multi-feed detection apparatus may include an ultrasonic transmission unit, arranged on one side of a conveyance path configured to convey a sheet-like member, for transmitting an ultrasonic wave toward the conveyance path, an ultrasonic reception unit, arranged on the other side of the conveyance path, for receiving the ultrasonic wave from the ultrasonic transmission unit, and a multi-feed determination unit for determining, based on the reception result of the ultrasonic wave received by the ultrasonic reception unit, whether multi-feed of sheet-like members has occurred. The ultrasonic transmission surface of the ultrasonic transmission unit is inclined with respect to the conveyance path, and the ultrasonic reception surface of the ultrasonic reception unit is arranged to be almost parallel to the conveyance path.