The unit is made up of specially-trained local policing teams, and will provide 'consistent, high quality support for robust investigations'.
Chief Constable Sir Stephen House and Scottish Cabinet Secretary for Education and Lifelong Learning, Angela Constance met with officers at the launch of the initiative this week in Livingstone.
Speaking of the NCAIU, CC House said: "Child abuse - including child sexual exploitation - is a complex, challenging area of policing. We owe it to all those affected, whether now or in the past, to thoroughly investigate each and every report we receive.
“The NCAIU is about providing specialist investigative support. However, part of our success in delivering child protection is local officers working with their partners in communities throughout Scotland."
Angela Constance said: "The launch of this new police unit should enable more to be done to target, and bring to justice, those who seek to harm children. It is a welcome development.
“The Scottish government is committed to doing all it can with partners to ensure we have appropriate people and procedures in place so more children grow up free from the fear of abuse and violence in their lives.”
The unit began a phased implementation in January this year with the creation of the national hub in Livingston and investigation teams in Aberdeen, Inverness and Dalmarnock. It comprises more than 40 officers nationwide.