Duplex scan indicative scanner, scanning apparatus and scanning method

A duplex scan indicative scanner includes a sheet passage, a transporting mechanism, one single scanning module, a duplex indicator and a connection interface. The transporting mechanism transports a document past the sheet passage. The scanning module scans a first side of the document passing through the sheet passage. The connection interface is electrically connected to an electronic device, the duplex indicator, the transporting mechanism and the scanning module. After the electronic device has controlled, through the connection interface, the scanning module to scan the first side, the electronic device controls, through the connection interface, the duplex indicator to output a duplex indication message to guide a user to place the document or a second document, so that a second side of the document or the second document is scanned by the scanning module. A duplex scan indicative scanning apparatus and a duplex scan indicative scanning method are also provided.