A coin processing apparatus includes: a slit provided on a downstream-side conveyance path or at an entry of the downstream-side conveyance path in a coin drawing section for a storage to pass a coin having a coin diameter equal to or less than a diameter of a target type of coin to be drawn; a coin bias mechanism configured to bias a conveyed coin; an outer diameter sensor configured to detect whether a coin passing through the downstream-side conveyance path has an outer diameter of a target type of coin to be drawn; a material sensor configured to detect material of a coin passing through the downstream-side conveyance path; and a hole sensor that detects presence or absence of a hole of a coin passing through the downstream-side conveyance path.